machine shop for exhaust header surfacing/decking?

I have a set of custom headers and the flanges appear to have distorted slightly during manufacture/JET HOT coating. Can someone please recommend an outfit in the SLC that can surface/level the flanges? Thank, pic for reference

I've had manifolds decked at Hunter Machine, if you want a name. But I bet any machine shop could handle that easily.

HF belt sander. (no seriously)