tail boom repair

I'm hunting for a first glider and have come across a few with repairs to a broken tail boom. In such a major repair, how do the shops insure that the tail group is realigned to its original position? Do they use jigs built to factory specs? Or rely on measurements? Or just eyeball it?

Is it customary for a buyer to measure a glider that has had such a repair, and if so, where does he find the specs? For instance, the distance between wing tip and tip of horizontal stabilizer?

Maybe this just worry-wart thinking, but I've had experience with out-of-alignment repairs on a tail dragger that caused it to fly slightly skewed - and a little slower. Is this an issue with these long-winged ships?