Thank you for your words of encouragement Philatarium, and all the rest of you folks. It has been a rather challenging week and a half for me, which kept me away for a bit. But now it's time to wrap this up. Here is the rest of the story on the alternative three cent design series.
FIRST ALTERNATIVE DESIGN; DIE STATE II
At this point we come to our first real roadblock to a complete illustrated story.
In 1941 Brazer included a listing in his Essay catalog for what is logically Die State II, which differs from the first die state by the addition of lettering to the blank entablatures as "THREE CENTS" above and "UNITED STATES POSTAGE" below. The listing for his 147E-B acknowledges two forms, both on India paper, with and without the vignette of Columbia pasted in. For this listing he provides a photo illustration of the paste-up model. On inspection, to the limits of what a halftone may show, it appears that the surrounding ornamentation is identical to that in die state 1, and the paste-up vignette appears to be the same vignette of Columbia we have been seeing.

Unfortunately, neither form of this essay has come to the market in the past 25 years, and I cannot report on their present existence or on the details of their fine engraving, such as the rose-engine fill in the numeral. We can be reasonably assured that the item illustrated in the Brazer catalog exists, or existed in his time, but its whereabouts are unknown. As for the item only described in words, we have no solid evidence that it exists except for the fact that Brazer gave it a normal listing. For these reasons, Scott only lists this die state with the vignette paste-up in place, which has been given the number 147-E4. Scott follows Brazer in listing this in two colors, black and green, and even gives pricing that is in accord with the other essays in this series. But these are so far unsupported suppositions by the catalogers, and need to be verified. After this gap in the story, the chronological sequence of the remaining material is less certain.
ALTERNATE DESIGN II
Continental produced a second style flat top numeral design utilizing the same outline large numeral three but with different ornamentation. The example on the left is a die print on India which was die sunk on card and reduced to about 45x45mm. This is the only example known in this format in black, but the example on the right* is the same style in hybrid format printed in green. These are Scott listed as 147-E5 but without differentiation of the format.

*Siegel auction 1010
This is an example of this essay type in green on India reduced to stamp size and not card mounted, a third format but not listed as such. The unusual "ghost bubble" shading in the vignette frame of the hybrid above also appears in this example off card, and is now known for the prints in black (see below).

The numeral has the full lettering for denomination and country, paralleling the second die state of the first alternative design, but which is not available for comparison at present. (Comparison here will be made with the first die state known for both essay types.) Note in this comparison that the contours of the large numeral "3" around the location of the vignette frame are not the same for the two designs. The frame in the example on the right is narrower than in the other design, and it is shifted somewhat to the left, thereby changing the thickness of the numeral, with less on the left of the vignette, and more on the right. In addition the Rose-engine work in this second design is not identical to that of the other style. Perhaps the greatest difference between the two, and the feature noted by the early catalogers, is the replacement of the comparatively light foliate ornamentation with a darker ornament of tightly scrolled acanthus shells.

As with the first alternative design, this one also appears as a paste-up model with the same vignette of Columbia mounted in as we saw before.

ALTERNATE DESIGN III
The item in this picture was never listed by Brazer and may never have been seen by him. This die print was pulled on India paper which has been cut to the size of the design, then mounted on India block sunk on card. It is presently listed in Scott as 147-E2, but it's actual position relative to the other styles of this flat-topped numeral is presently unknown. Although it is listed in both black and green, so far this is the only example that has surfaced. The listing in two colors as well as the pricing may be attributed to "paradigm pressure" based on conformity with the listings in the series around it.

Comparing this with the other two designs, we immediately notice the absence of surrounding ornament. The disposition of the oval vignette frame is more like style two (on the right) than that of the first alternative design. Similarly, the details of the rose-engine fill in the numeral resembles that of the second design type. In all, this appears to be a stripped down version of the second design type. But these three are all from distinct dies.

When we take a closer look at the new die print itself, we can see that its condition is atypical for a die print from this series. Significant remnants of printed horizontal framing lines appear at top and bottom, and short line fragments can be observed left and right too. This all around frame-line hints that some kind of rectilinear frame was being considered, in addition to the foliate ornamented frame. In the case of this print we also note that there is a shadow arching beneath the upper and lower lettering. The close-up on the left shows that this was not engraved into the design but was added to the die print to show where some additional engraving was desired. Most of the discoloration of the white areas in this print is from pencil as well.

What makes this essay such a conundrum is that it is not yet possible to tell whether it preceded the second alternative design type or followed it. It was not formed by the removal of the surrounding ornament from the first alternative design, but it may have come from a reduction of the second design type with a circumscribing frame added. Or it may have been an early stage in the development of the second design type. Here I may add the note that we cannot yet be sure which of the two series of essays came first, the study of three cent designs or the sequence of "round figure" denominations.
For now, these are all the large numeral essays known to exist from the 1869 effort by the Continental Bank Note Company to win away the contract for postage stamp production. No plates are known to have been made for any of them, and the entire effort was discarded by the Government who preferred to keep the contract with the National BNCo, and have them produce new designs for new postage stamps. This they did with their profile bust series, and ushered in the era of what we today call the Bank Note Issues.