Wish I could recommend a shop to ya, but unfortunately if it ain't an AR or Cerakote, most places look at you like your crazy or try to charge twice what it's worth and ship it off themself to someone that can do the work.
Curious what's are you trying to re-blue? I have done a few of my own just applying heat to Casey cold blue and have had some great results. Most important is the prep work. It may be something you can knock out yourself in the garage over the weekend and save ya some doe. Cold blue with some heat torch or heat gun worked great for a couple pistols and barrels I've done. Blended with 0000 steel wool. Give em a nice deep blue finish.
Deep South Bluing. I cannot say enough about the quality and workmanship that Mark shows in all of his work. I have had several done by him and they were returned far better than factory. Truly top notch in every way. Here is a link to his business: https://www.manta.com/c/mx4yy8h/deep-south-bluing