I am trying to decide between two hypotheses: (1) these two covers were struck with the same device, vs. (2) they were struck with different devices.
I am assuming: they were struck with genuine PO issued devices because the covers are signed by the Postmasters at the time they were postmarked (Story, in 1942, and Stanley, in 1945).
I lean toward the view that they are the same device.
I've drawn lines from the T in Victory and the T in VT, and from the V in Victory to the bottom of the third killer bar. In each case the first line skirts the right side of the 9 in the year and the left side of the M in the time stamp; the second line transects the year in approximately
the same location, along the bottom of the upper portions of the 9 and 4; the variation in the 2 and the 5 can be attributed, I believe, to the fact that these are two different slugs.
Thus far, I think the evidence is consistent with this being the same device, rather than evidence of two devices.
But then there is the "flyspeck" just inside the circle of the CDS and just above the line running from V to the bottom of the 3rd killer bar. I presume this to be an irregularity in the surface of the CDS that picks up and deposits ink. And I think it adds to the likelihood that the same device was used to strike both covers.
Below the covers is an image in which I have overlain the postmark on the top (Story) cover with the postmark on the bottom (Stanley) cover, reversing the colors of the bottom postmark to provide contrast. The lettering around the inside of the circle does not line up because of a slight difference in angle at which the handstamps were struck relative to the top edge of the cover. But if the circle is perfectly round then this angular offset should affect the way the circles appear.
It has been suggested that the thinner and sharper appearance of the circle and the lettering of the top circle is evidence proving that these are strikes from different devices.
But it looks to me like the differences could be explained by variations in the amount of ink picked up and deposited when the covers were struck. In the top cover, there is a light area in the circle under the VT. This is probably a combination of a depression the circle of the CDS at that point, as well as less ink being picked up and deposited, because it appears that while the circle is more fully filled in under the VT in the bottom cover, it looks like same depression in the circle is present under the VT because the areas of the circle to either side (e.g. the 7 and 5 o'clock position) are thicker and appear to be more uniformly inked than the area directly beneath the VT. The difference in the "flyspeck" also seems to reflect picking up and depositing more ink in the bottom example, as well as what we see in the R of VICTORY. I think there is also a variation in the surface of the CDS that picks up ink above the period after VT but is barely if at all present in the bottom cover so I didn't point it out. But I see it often in other Victory, VT covers. In any case, these differences that can be attributed to variations in inking seem to me to be more consistent with a single device being used than two different devices.
I am not trying to prove a particular theory, I am just trying determine which best supported by the evidence.
Thoughts an opinions are not just welcomed, but invite. And if you see evidence more consistent the hypothesis of two devices, point it out, please.