Elevated top half with a stack of insulation plates. I can lift the half with one arm and push the plates under bulkhead to support while cutting holes. This is lightweight building. I am used to heavy oak wood so it is quite a relieve to work with these materials.
End of float need a little adjustment but these half's fits very well, within millimeters.
Checking where to put battens before gluing so edges match up. It is like edges pops out of shape when released from mold, but easy to match with lower half, and once glued they stay in place. Note that I still wear ear protection, my wife is present.... ;-) Sorry but that was just the only stupid comment I could think of now.