The Olathe Poste as noted above in a previous posting has a Rosback stroke perforator (U.S. Kiusalas 12-67 gauge measurement) and Anna Banana has a Rosback rotary perforator (U.S. Kiusalas 12.5-63 gauge measurement). They both perforate artistamps with their perforators. Her website is at
http://mypage.uniserve.ca/~a_banana/ Both of these perforating machines were used to perforate U.S. stamps. The Rosback stroke perforator was used to perforate U.S. revenue stamps from 1914 to 1958 and the Rosback rotary perforator was used to perforate a U.S. postage stamp issue from 1919 (Scott 536).
At one time, I was planning on making labels that showed a picture of each perforator with each type perforated by the same pictured perforator as a collectible stamp label picture gauge, but it would be an expensive undertaking and I wasn't sure about how much interest there would be in these labels so that I didn't do it. Here's how they would have looked like.

