Ive always thought they were vintage to the early 50's. I owned a couple of the St.L Browns ones in the early 80's, and they had rust and age back then. I just searched and the ones that normally pop up have a smaller image that what I remember.
I believe these are the original vintage ones larger (larger image)
http://www.barkermuseum.com/MuseumLi...21&SRT=1&SRWD=
I believe the fakes from the 80's look like this (smaller image)
http://www.ecrater.com/product.php?pid=4339758
The ones that are ALL fake for sure are the Cobb, Ruth, Wagner etc. ones.