Well, what do you date that catalog you bought as? 30/31? It's got chevy six (29) stuff but not Ford V8 (32) yet is that right? The Boeing aeronautical school mentioned was founded in 29. so it has to be after that. Also, does it mention the "techniheat" process? That was in April of 31 so it may or may not have been mentioned in a 31 cat. depending on publication month. If it's not mentioned that puts the catalog to pre April 1931. My guess is your cat. is probably a 31 and the 31 referred to on the AA website is a 32.
It depends on which catalog you speak of. I have one purchased off Ebay last December that is early 30s. I would date the catalog 1931 or 1932, but as of yet there is no clear evidence of it's exact date.
The 1600 Series, as represented in the early 30's catalog I have, are speed wrenches. The model 1612 would have represented a 3/8" opening on a 8" below bend speed wrench.
I rarely leverage AA for my research, and it's been a good while since I've read the Thorsen write-up there. I should probably do that again soon.
My approach is to have the wrench in my hand for further research.
Its good to see other's interested in, and knowledgeable of, Thorsen.