22 Win Mag over 410.

Exposed hammer. Selector button on the side of receiver, and not hammer.

Stamped Model 24B

Anyway to get a DOM?

No date stamp on it Jeff? Seems like it should have one.

Where is the stamp supposed to be?

Not too familiar with the 24's stamp location but you should recognize the date stamp it'll look like the 99's.

Usually on the barrel.

Chicopee Falls, or Westfield? That'll narrow it down to the decade..

Westfield

So 1960 to 1968..

24M shows up in 1961 as a 22 Mag/410 with that configuration, and disappears by '65. So early 60's. Don't ever see a 24B listed, unless it's '62-'63 and a renamed 24M. Likely shown in the catalog under one model name, and stamped with another. They would do that... Definitely should have a date stamp on the barrel.