Interesting...and man it would be nice...on paper. But few things...
You're going to be very hard pressed to find a full time career doing this, even moreso trying to support a family. I know Red Lion...not much around there. A few good pinheads though. And you're near York which is a plus once a year!
Basically I think unless you're a high end master of restores you may not be able to easily support a family. I suppose the other way is if you're a very talented designer/artist/programmer and you could work remotely for the big guys.
If you're just talking about basically doing some playfield swaps, tech work...it's going to be tough to make a good living. I fix a few local machines and make a few bucks. Usually enough to pay for a nice dinner now and then.
Honestly, I think once you depend on this for supporting a family and paying the bills it changes everything. For me, the few times I work on machines for money it's not the same. When I tinker on my own machines I have all the time in the world. If I want to go nuts on a machine or just clean it up a bit...it's all me. When it's for a client, they have timetables. They have demands and requirements. I had someone tell me once to just re-use rubbers. It irked me. When there is a client that's asking for their game to be done in a week or two as you promised...well when that week is creeping up and you just don't feel like doing it you don't have the freedom to leave it be like it is your own machine.
That said, anything is possible...there may be a huge untapped desire for a full time guy in your area and you never know until you put out the feelers and see!