I had the same issue too. The first thing I checked was whether the hingeline was straight by running a stringline through the middle. It was dead nuts on. So, the problem was resolved through a combination of re-bending the leading edge of the elevators and by moving the rod-end bearings one half turn at a time. I too got very good at taking the elevators on and off, but there is no other way around it. Trial and error until it's right.
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