I do, fixed the light seal on my Mamiya RZ 6x6 back. They are good. However I couldn't negotiate price with them. I think the guy there didn't understand what I said. It went like this:
me: hey can you give me a discount for first time customers
the guy: no, no discount. why I want to do that?
me: to build customer relation
the guy: no I don't want to do that
me: you don't wanna build customer relation
the guy: no...
So I think he didn't actually understood what I said. you could try negotiate but I couldn't get anything from him.
they offered me better rate than Camera Doctor in 30th street..
Good luck