You did quite well getting that rifle for that price. I'd suggest have the barrel rebored and rechambered to either .25-20 or .32-20, both of which are excellent small game cartridges and use the same basic case as the .218 Bee, which means no other modifications would be required. I've had some success with reboring done by Dan Pedersen, whose web site is http://www.cutrifle.com/index.html.

I'm a bit of a small frame Martini nut myself (have two rimfires and three centerfires currently) and think they are a lot of fun to play with.