Mystery snap on tool

[JWILL]

Can anyone identify this mystery tool?
Only thing visible is snap on logo

 

[bonneyman]

Old valve adjustment tool? Square ratchet goes on left detent, and a socket goes on the right detent. The short handle lets the other hand hold the contraption steady.
Maybe?

 

[dscheidt]

an image search, using your picture, turned up a pointer to an ebay listing that was titled "sg7 ratchet adapter", which is probably related to this patent https://patents.google.com/patent/US1443413 which is a weird manually ratcheting (you slide it up a spline, turn, slide down) t-handle. Very early SO, the patent is 1920. but it's hard to find anything else.

 

[J.A.F.E.]

The early ratchets used a female drive opening and needed a drive plug to hold the socket. This replaced the drive plug and allowed manual turning of the socket or a place to grip while breaking loose.

 

[KnurledNut]

 

[cgrutt]

Interesting. So the "anvil" on those flat ratchets was actually a removable "plug" and tool above could be used standalone or attached to a flat ratchet? Also looks like a replacement "plug" was sold separately, assuming for wear and tear? Learn something new everyday...

 

[Steven 33]

Can anyone identify this mystery tool?
Only thing visible is snap on logo

My favorite snap-on tool! If it's something you would part with I'd be happy to trade or purchase it. Just throwing that out there