I've lived here all my life and can tell you without reservation I know of NO Gunsmith on LI that I'd recommend! That is why I have done all my own work for 40+ years now. Seriously (and sadly), I can tell you many horror stories and not many good ones from friends who have used LGS here. I'd suggest that you seek out someone who really knows the M52 and who has great reviews.

This is especially important when working on a discontinues model that parts might be hard to come by. I wish I had better news for you but you asked and that is my honest opinion. Good luck with your hunt. If you don't mind, what are you looking to have done? I am just curious......