The two wooden supports LWX and LWY need top be correctly positioned but the plans directions and the plan sheet are different by 0.2". After much thought and discussion the critical measurement is placing the pieces so that the spar can be later fitted AND so the back seat support will fit without sticking out of the bottom or into the spar box.
I also spent some time with the landing mounts which later go here to ensure I understood where things were going and that my placement would work. The sparbox must fit and I wanted to ensure that the lamding mount bolt holes were going to be correctly placed. I also wanted to ensure both sides matched so the back seat was not going to sit in a cooked manner.
The parts were then positioned using 2mm nails after I was sure it was all OK. After this trial fit and prep work the parts were floxed into plaxce and weighted with lead and clamps until cured.
