The 7081 service manual contains a partial guide to the setup, testing and calibration of these meters, but the factory test and calibration procedure documents have a lot more detail. It is interesting to note that they actually took weeks to pass through the calibration stage, especially every tenth unit which was kept back and rechecked at 8 weeks and 13 weeks.
Unfortunately it doesn't contain the source code for the calibration programs which I believe were run on a Commodore PET, but I hope it is nonetheless of some use.
The file can be downloaded from here:
http://www.perdrix.co.uk/Solartron70...mozTocId453904
Cheers