Beavertails show up with that Rueb patent number (1934) and a later improved Rueb patent number, 2,232,477, granted in 1941. I have one of each. I am sure there are guys here who have several. I am not well-versed enough in S-K production, nor do I have enough sets with beavertail ratchets of both kinds to know if those dates can be definitively used like brackets, but, unless they continued making and issuing the ratchet with the earlier patented mechanism in sets after the improved ratchet mechanism was introduced - which seems highly unlikely to me, I would say the early patent ratchets were made between 1934 and 1941.