CPT boards

I borrowed a pile of scrap 1970s-era PCBs from my local recycler yesterday, just to make sure there was nothing important among them before they go off for processing. Among them are six boards branded as CPT, which I assume (as I'm in MN) is the CPT Corporation that was in Minneapolis. The double-sided boards are organized in five rows of five ICs, with 44-way edge connectors and IC date codes in the 1973-1977 range. I seem to have p/n's 910012, 910014, 910015, 910017, 910018 and 910022. In addition to this there's a smaller board which references "deck 1 heads" and "deck 2 heads", and appears to have a p/n of 910025. Does this ring any bells with anyone? The Wikipedia entry for CPT mentions the 'VM' machine in 1976 with dual tape units, so I wonder if they're from one of those... if so, I'm curious if there are any surviving intact examples out there (or other info, there doesn't appear to be any CPT stuff on bitsavers) cheers Jules