How Do I Tell If This Is A True 579?

I have a 2c carmine Washington with perf. 11 x approx 10.

I see in the catalog, that it should be 19.5 x 22.25 ... is that the design size, or the total stamp? It says it was made by cutting down a coil stamp, so doesn't that mean the whole stamp should be smaller than others of the era?

This stamp is not smaller than a regular 2c. Or if it is, then the difference is miniscule, so I am confused.

Also, the perfs are not exactly 10 vertically - very close, but maybe more like 9.8 or 9.9

How on earth do I tell if this is really a 579?

Can you provide us a scan of the stamp?

(By the way, the 19.5 x 22.25 measurement is the size of the stamp design.)

The measurement is the design area of the stamp. The 579 was coil waste made from perf 10 vertical coil (Scott 599) printed and perforated web. When the printed web was less than 500 stamps long is was cut on the joint lines and ran through the perf 11 perforator in the horizontal direction. Later the BEP discontinued this process and spliced the webs togethe to produce the coil lengths needed.
The 579 and 599 are the same size.
As for the perf 10 the digital size is 10-7992 which calculates to perf 9.85

The news that the perf should come out to 9.85 is encouraging, because this appears to be just under 10. Here it is:




As I see it, if not 579, it could only be 634 (perf 11 x 10.5 and design 19.25 x 22.5)?

And a 579 would be perf 11 x 9.85 and design 19.75 x 22.25?

This one measures right on 22 by my eye, which is sort of helpful. And I would swear it is closer to 20 than 19 the other way, which along with the perf. implies genuine 579?

Am I missing another possibility?

Have I confirmed it is really not just a 634 or some other type I haven't spotted in the catalog?

Thanks.

This is definitely SC 579. Nice find!

Thanks chasa! I see in the catalog that stamps like this that are worth more used than mint need contemporaneous cancel verification. Is there any way to do that with wavy lines like this?

Also, can I ask another id from someone? I am thinking this is 499 (Type I). It is definitely Flat Plate, but the Honolulu precancel comes in both 1917 and 1918 printings. I don't see this being Type V +++ though. And it doesn't seem to be Ia? Trouble is I don't have many properly id'd stamps in my collection yet for comparisons.

Thanks.

This is the SC 499 type-1.

Thought so. Yippee. Progress is being made.

Are you basing that on the very light edging to the toga button and rope? Or is there something more telling?

My eyesight isn't good enough to tell how many lines there are in the ribbon curves -- or maybe I have just never seen a stamp with more than one line so I don't know what I am looking for.