Robertson STOL kit drawings

[B2C2]

I have a problem where the flap indicator is out of calibration on my Robertson equipped 1969 T337D. The flaps are moving through the correct deflection, but the indicator shows 2/3 when they are full down at 25 degrees. Other than the calibration issue, the Robertson system is operating as expected. I suspect that the flap indicator cable connection in the wing is out of adjustment based on the maintenance manual that I have which refers to making a mechanical adjustment at the bellcrank in the wing or at the flap lever in the cockpit for the cable. I called Sierra industries and apparently there is no installation manual for this, just a set of 4 foot by 12 foot drawings, that cost $650 for the set. I have the operating manual and maintenence manual but these don't have any parts lists or show the detailed installation. Does anyone have a set of these drawings and could take a picture of the portion that shows the details for the flap indicator cable interconnection point in the wing? Alternatively has anyone had a similar problem and found a different solution?

Thanks