NAPA Battery Electrical System Tester (Associated 6042 ??)
This tester doesn't have a model number on it but, to me, it looks identical to the Associated part number 6042 Battery / Electric System tester, but I don't know for sure. I hooked this up to a battery and it showed the readouts in the 2nd picture. This is as far as I have been able to test it.
The amp pickup clamp is missing a bolt or nut on one side (see picture).
This is located in Phoenix at about 40th Street and University, just south of the airport.