mechanic for an old boat?

[Berrycat]

Hi, anyone want to recommend a marine service that likes and is good with old boats? I have a vintage bowrider and am thinking of replacing the engine (engine got messed up with some aftermarket parts put in by the second owner..) but my current boat mechanic has had the boat out for repairs with no progress (and no apparent work) since the original put in date weeks ago and I don't think they're really interested.