I checked the packaging for my Terry Medaris Art Stamps and unfortunately, there is nothing there about whether or not he is an angel company. The package does indicate that the stamps are made in the US and that the company is in Tucson, Arizona.
I ordered a bunch of stamps from his online site about a year or so ago and I was very pleased. I recall that there was small mix up on one of the stamps and it only took one email to cleared it up (beyond my expectations, I might add).
As Anna indicated, they are unmounted, red rubber and are quite large. The cowgirls on the fence measures 3 x 5 and the cowgirls standing all in a row is about 3.5 x 5. Anyway, here's my take on the cowgirls:
Cowgirls Just Wanna Have Fun by efromhawaii at Splitcoaststampers
HTH
Erin