I don't know about up and around Michigan, but around here every shop is so specialized. There are very few GOOD automotive machine shops. Dayton supposedly is one of the biggest machining centers around with over 600 shops in the metro area. BUT, they all either cater(ed) to GM/Delphi which pulled out or to the Aerospace industry because of Wright-Patterson AFB, the AF Research Labs, or G.E. just north of Cinci.
The shop that ultimately did my EDM work is a production shop. They just happened to be able to fit me in on a small machine while they were changing setups/jigs on the bigger machines. It took 2.5 hours of cycle time to get mine out, and even then some of the threads had to be taken out to get all of the bolt out. The auto. machine shop still said it was too deep for him to put in a bushing (hard to believe). But as luck should have it he knew a guy that owns a tool and die shop down the road that had invested in a Time-Sert kit for a Caddy NorthStar V8 that uses the same size and pitch head bolt. The NorthStar head bolt is just slightly longer. So that's getting done this afternoon and then it's going back to the auto. machine shop to have him just take the glaze off the cylinders so the rings will seat without issue.
Gobogie, let me know what the final result is from the shop there. I may be able to help out in some way, shape, or form. If nothing else I can ask my uncle about shops north west of Ft. Wayne, IN since he knows them all. (He's been building and racing all manner of cars since he was a teenager).