I was in the same spot a year ago with my Marvel Schebler MA4-5 carb; a local A&P referred me to El Reno Aviation in OK, said they did good work on carbs. So I called 'em up and we talked overhaul price; the initial quote was around 5-600 bucks with yellow tags and all that. Then I mentioned it was going on an RV... "ohh, that's different" says he. Yellow tags/paperwork? Don't necessarily need all that, which brings the cost down a bit. So I sent him the carb directly and he went thru it; new float, screws, gaskets, bushings, etc. Looks like new, no yellow tags, had it back in 2 weeks... cost $343. I have a whopping 4 hrs run time on it so far, and knock on wood, it's running fine.
I think this is a side gig for him, not done thru El Reno... if you want contact info, PM me. Not sure if a Stromberg carb would change things, but might be worth an email or phone call.
JB