F15A Trying to Identify

[Grant Bowker]

The standard F15A rear spring pack had 10 leaves, according to the parts list the "Machinery" truck had 12. Are Mach-KL and Mach-1 two descriptions of the same truck or two different configurations?
Before hearing Rob's explanation of PCC, I wondered whether the lettering might have been RCS for Royal Canadian Signals. I still sort of wonder whether they would have gone to the trouble of stenciling the door of a surplus vehicle or would have freehanded it?
Another possibility would be that mix and match happened. Knowing how the wrecker's winch is driven might help clarify this as the only F15A variants come to mind with a power takeoff are tankers. PTO drive from the transfer case would be an addition, two speed case would be a changed part which would suggest that other mixing might have taken place.