I have noticed some discussion on relay problems and the reverse relay on E12 and E15. In the back of my product service manual, covering the whole range of ET's, there is a 4 page service bulletin April 10, 1972 which says "This troubleshooting guide is provided to enable the Elec-Trak tractor mechanic to rapidly find the cause of burned reverse relay contacts in the E15 and E12S".
If this would be helpful I will throw it on the scanner. Please tell me where to send it, what format, what resolution etc.
I saw a mention of some indistinct manual pages. I may be able to re-scan some of these from my service manual if required.
South Australia. E12S.