Tow Dolly Woe

What kinds of shops are you looking at?

Any trailer shop would welcome the business, but I suspect you are probably just hitting up automotive mechanics. Shops that work on cars generally do not work on trailers.

I would think/hope any trailer shop that sells boat trailers would be able to service a tow dolly.

How about a marina, a lot of boat trailers use surge brakes?

For us, the key has always been to find a good independant shop that you make a long term relationship with. We have 2 that we use, and I've taken oddball stuff in like a pressure washer that stopped working vs. taking it to the high volume small engine and lawn mower shop we bought it at. I even had them do brakes / bearing repack on our TT some years ago.

No, this does not help you now...but keep looking. Talk to them. Get a feel for the place. Search google maps for high reviews. You'll find the shop you need...it just may be a one man show vs. a chain. Lastly, don't overlook tire shops. We have a semi truck tire shop in town and they do RV's and TT's all the time...they even rebuilt a driveshaft for a classic truck I had.

I worked on my own surge braked trailers, but not for hire.
Most CMV LEOs that I have talked to don't like surge brakes for the same reason; It is hard to test to be sure they work like they should.

Most owners neglect utility trailers until something goes wrong, and then it is terrible to fix or get parts. In short they don't want the headache.