Hi All, Champ 54 here. I have 2 1970's electronic tune up machines that I would like to use on my 1974 Datsun 260Z and other 1970's vintage vehicles. I am trying to find circuit diagrams for each of them. I see a post on this forum done some time ago but there was nothing to indicate if they found anything. I have the operator manuals for both machines but really need the technical circuit drawing if I can locate some. Any assistance would be greatly appreciated. Looking for circuit diagrams for Vane VP850 and Repco 646 tune up scopes.

Thanks