Glenn, can you put that description of how to get rid of cone error in laymans terminology.
I'm not Glenn, but I've done this with my old G-11. Set your mount up pointing north, exactly as you would for regular viewing. Turn the RA until the counterweight bar is horizontal pointing toward the east. Turn the OTA in DEC until it's pointing at Polaris. Yes, POLARIS - not the NCP!!!!!!! Adjust the AZ manual controls until Polaris is dead center - go ahead and move the OTA in DEC to center Polaris because the DEC position doesn't matter at all here. Got Polaris centered? Good! Now rotate the whole contraption until the counterweight bar is again horizontal, but now pointing toward the west. Move the OTA in DEC and try to get Polaris centered again. If you can't, you have cone error. Determine which end of the OTA needs to move away from the dovetail plate to center Polaris and start shimming until you can repeat this exercise with Polaris staying centered. Remember, movement in DEC doesn't matter - move it until you get Polaris centered as well as possible. I used an old set of metal feeler gauges and kept moving up/down in size until I got the OTA shimmed by inserting them in between the dovetail rail and the OTA rings. Am I making myself clear?