I did the same trick with the stretching the string between the wingtips. That is how I arrived at the point 1" behind the spar. I realize this is farther back the the ususal "balance on the spar". Hdkeney: what did your measurements translate to at the fuselage relative to the main spar? With the weight you added, I assume your test flights went OK?

I appreciate all the input. I am going to replace the plastic clevis but my LHS did not have the 2mm metric Sullivan clevis, so I need to order. They look to be metric anyway, as my 2-56 Sullivan did not seem to fit?