These guys have modded more of their watches than most of us have had hot dinners, so I think it pays to listen to them!
The answer to the riddle is not to look for a person that can both service and mod a watch, forget that. Let's work to find people that are at least good at one of them, let alone two.
For the ETA movements - that's the easy bit. If it's an asian 7750, less easy.
On the modding side, time for folk to practice. Just don't go charging other people for blowing dust off the dial until you have a proven track record of knowing what you're doing!! (Hint: Deep breath!)
Ziggy is doing us a massive favour in the long run; he can't be everybody's hero - it's time for other folk to step up to the challenge (and the scrutiny that comes with it).