Great thread and I've loved reading it. I never made it there and first I knew of it but S.E Michigan has had and still has some good shops.
As a kid I loved going to my cousin's shop in Lapeer, Mi., Roy's Sporting Goods in the '50s and '60s. Sadly he closed around 1970 and I have but a few items from there.

Guns Galore in Fenton was mentioned here. I went to H.S. with the second generation sons now running the business and I expect they're tired and not giving their best as far as customer service, weekdays are best.
I've dealt with Williams Gun Sight in Davison right down the road from me most of my life and the three generations since the 1930's. They've since sold to a good guy and gun nut/hunter. They have a good supply of older S&Ws and will deal.
Another in Flint is Bullock Guns, a smaller shop but fair and often have nice older S&Ws when they can get them.
Another north of Davison in Otisville is The Gun Barn, son of the Gun Barn owner in Highland, Mi. Some nice older pieces a little high but deal with cash money.

I'm not wanting to take away from this thread as I've found it most interesting but wanted to mention to some in the area there still are some good dealers around.