Heuer 1163 Chronograph Repair

I have 2 Heuer 1163 chronographs in need of repair. I had a watchmaker open both and was told that aside from needing a good servicing -- each had a broken part in the movement that would need replacement. (Or I guess repair if possible) I'm no expert here, but if I heard it right -- the broken part was preventing engagement with the pusher that sets the chronograph in motion. Needless to say, this watchmaker did not have these parts sitting in his workbench. Thus my question: Does anyone have a recommendation of someone who specializes in vintage Heuer restoration, that might also have needed parts on hand? One is also missing a pusher, but I understand that new replacement pushers are available if a vintage replacement can't be found. Thank You! Jim

I live in the US and Thank You Very Much for the advice. Jim