It was a FUNCTIONAL gun before it was disassembled right?
Contacting the factory or a Beretta Dealer might be your best bet. If you're military or LE they will replace all the springs/pins and true it all up, probably for free. Otherwise I'm sure there would be a parts/service charge. Since it was only $25 with any charge you'd still be ahead of a new one!
I WAS a qualified Beretta Armorer, it expires after 3 yrs but the basics never change and I haven't been back. There aren't any real heavy "gotchas" with them. The one thing I won't touch, and Beretta specifies it HAS to return to the factory for, is reattaching the locking block to the barrel. There is a fitting process that to many people weren't doing right and all it did was shear the block.
Doesn't require any really special tools either. Screwdriver, a set of punches and a "spring hook" (nothing more than a small crochet hook with the end flattened).