If you look on eBay for "Ford brake wrench" you will find all kinds of vintage brake adjuster wrenches. Make sure they are 7/16" 8-point wrenches so they will fit a four-sided adjuster. I have a bunch of brake wrenches for early Fords that I inherited from my grandfather and my dad, on two different sides of the family so it must have been really common to adjust your own vintage Ford brakes. I'm not sure how much of an offset or if any offset is needed for a Model A, and I have a Model A??? I bought it, had a stroke and have never been under it yet. I stepped on the brakes about three time taking it off of the trailer and into the garage, that's my brake experience with Model A's. I was ASE Master light and heavy Mechanic which included a light brake license and a heavy air brake license. There wasn't a single Model A question on the tests, imagine that. My dad restored Model A's when I was young, and I never paid attention to any of it. I was an early Mustang guy, at least I stayed with Ford.
Here's me with mom and dad and there '31 roadster behind them. I'm guessing about 1963. That was his daily driver. He restored a lot of Model A's in the 60s and 70s including this '29 station wagon. Every nut was a thick-headed Ford original. He did his own paint work on the clothesline. Then he switched to Flathead V8 cars. I still have his '32 roadster and about a dozen of my own Ford "projects".