I tried Mike Pacak when I had my Utah but he didn't have a schematic for it. (I tried EVERYWHERE to find one)
Seems there are 4 *known* owners of United Utah pinball machines in the WORLD. (Even pinballowners.com doesn't have a Utah owner listed)
There's one in Rafael Lankar's Paris pinball museum, the ones you/David have and the one I recently sold.
Upside is you have a very rare game.
Downside is that a schematic may be impossible to find and it's no easy task to find another Utah to compare the wiring with your game.