Hi Chris
I cant help with the distributor, but in case you didn't already know, I thought you might wish to know it's army ARN is 30-197, it is showing on the REMLR ARN Listing extract below.
ARN WB Date Series Census Nomenaclature Engine Chassis
30-197 109 09/11/1978 Series 3 6006B Truck, Utility, 3/4 Ton, GS, with winch, FFR, 24 volt system 94124626C 94323588C
Body Notes
39301 GS??N? 188
I am sure someone on here will be able to help
cheers
David