I got one of these little shooters, and I just got one for my brother.
I did what LD said, and I did a few other things.
These guns have an inherit weakness in the scope mount. The scope mount rail is wood-screwed into the forearm stock. I took mine, and epoxied the rail and the screws to the wood. Then I topped it off with a log eye relief scope.
On my brother's gun, I drilled the scope mount holes all the way through, and used long screws and locking nuts to afix the rail to the wood. Another thing to make sure of, is that the screws holding the barrel to the forearm stock are nice and snug.
On mine, the guide rod was VERY bent, so I made one out of delrin, and replaced it. ON my brother's gun, it was fine, so we left it.
Once you work out the little details..its a neat little shooter. Oh, the B3 cleaning kit spring will fit it, but its the same spring as the stock rifle, so dont expect higher fps numbers.