Machine shop refuses to install exhaust valve seats

I don't know how other people run there business but if someone brings in a set of older heads I clean them and check them out, if the seats are so beat out of them that I don't think I can do the job and warranty the work I suggest they look for heads in a little better shape but if I start on there heads and they have a core shift or something that will not work out in there favor I stop and make a phone call. BUT AT THE END OF THE DAY IT'S MY NAME OUT THERE AND I WILL NOT DO WORK THATS NOT FIRST CLASS. When I do work I want the customer to take it to another shop and say take this apart and let me know what you think. I want that other shop to say this is a nice job and done right.
As far as a snap gauge I have them and use them for rough measurements but I have one bore gauge and I'm the only one that uses it I have had helps drop them or set something on them and totaly F them up so now it's me, I don't have to worry I'm the only person boring and honing blocks any way