I had, and quickly sold, one of these before--that one with a 1871 patent mark and completely greened patina. This one does not bear a patent mark that I can see and I think may not be quite that old, but still with a lot of years on it for sure. Still totally useable for sign making or all sorts of creative endeavors, but I'd hang it on the wall by a nail otherwise, and just give it a spin now and then! 

11" across including moving window; 10 1/4" across otherwise; 1" deep at  center handle. Good condition, with a little crinkling/bending to the brass in one area toward the middle and some greening around the "F".