I have no clue about this gun, other than it has a strong spring, and is in good  working order. There are no markings on this gun, other than a number on the bottom of the handle. Click on the picture for a larger version.   

Some guesses (so far) as to what this is, from various gunsmiths:

Bacon Mfg. Co. .32 Rim fire, (Valued at $125-$150)

Merwin & Bray .25 Rim fire, (Value = ??)