Not sure how common/uncommon these are? This one is stamped 707, and it measures about 7 inches long. Were there other sizes produced? Any info would be much appreciated, thanks.

Bob,
I've only seen the one size.
The   Popular Mechanics ads from 1925 & 1926  (MVWC 2011 PLIERS XTRA pg. 17  &  MVWC March 2013 pg. 19 )  make no mention of multiple sizes.   The patents (1,494,015  & 1,639,269 ) are in DATAMP.    Early production examples are marked "PATENT PEND. & CANTON OH."

Ah, thanks Stan. I won't spend a lot of time searching for an "808" model or a "909" then

What is the hole in the fixed jaw used for? Some kind of crimper perhaps?

Joe B

I wondered the same thing. It does not appear to have any function, other than "showing off" how the rack action works and perhaps allowing it to be cleaned easier.

I believe that hole is there to assist in visually confirming adjustment of the jaw to handle engagement. I don't think is for jaw opening size as much as its for gripping power when grabbing larger items.  At least that's what I get from the patent.