Nice find on the DW, I have some and the are the most accurate hand guns I own. There are some with "problems" depending on where they were made, but for the most part the ones from Monson, Ma. are the best.
As mentioned above DWK arms has parts and tools.
Sometimes called the 5th generation wheel guns, D.B. Wesson and Karl Lewis had some great innovations with the design. For a long time they were a good deal when you found one used, not so much anymore.