I have used one of those many times. The one I used had a place to mount the distributor in it. I really liked it as you could set the points,check the vacuum advance and centrifugal advance, see how much the play was in the shaft, if the lobes on the breaker were worn very much, and all of this prior to installing it in the engine. You could use it to set the voltage regulator on the generator, use the vacuum guage to set the carburetor and timing for the best engine performance, check for poor conections on battery and starters. It was a pretty good machine.
