post 1 does look like a standard deabolt was there at one time
post 2 Hard to tell but keyway looks like weiser. If you have any such keys see if they slide in/out easy. Then take the lockset to larger business locksmith to have it rekeyed or new keys made.
post 3 carefully measure or remove the wood block (most likely glued) and take it to the hardware store to find the bolt of your choice. Remember, over time these parts (hardware) shrink so you may not find one with the right hole pattern.
I got replacement keys for the Legge locks on our GB from Bellingham Lock & Safe in Bellingham, WA. (Generic, not Legge.) I would assume that a good locksmith in your area (CT?) would have blanks. Good luck!
Regards,
Scott