Am I Measuring These Stamp Right With Cal Gauge

Am I measuring these stamp right with cal gauge

You are measuring them correctly, but it does not mean a thing. The most important measurement would be the perforations which can be done with the gauge you show. Also, the back of the stamp is important - whether it shows ink or not. And oops, I forgot all about the all important watermarks,

Peter

perforations are 11 x 11

Your stamp appears to be flat plate #552. Can you post a scan of the stamp back?
Don

Overkill!

Compare design size and perforations with another stamp having known characteristics. The information in the Scott Catalog is not precise enough to be reliably used for design size measurement. Rotary press and flat plate stamps have enough differences in color, quality of impression and paper to enable visual identification without the need for detailed measurements of perforations or design size. In the worst case, a simple laydown test for perforations and design size should be enougth.

Link with info on making a 'template' from a known stamp which can help with flat plate vs. rotary
http://www.stampsmarter.com/learnin...methods.html
Don