I don't know how many folks on this forum have left off a Luger with a "gunsmith" that said he was familiar with Lugers, only to get back a disastrous(read:expensive)mess. I have been there and done that.
You are $$$ ahead to use someone that DOES know about Lugers and has worked on them for years....plus has parts available. A three hour drive is a "piece of cake"!!! I have done it many times to take 1911s and BHPs to a true expert on said guns. Make a day trip and do something fun along the way.