The A10 tube position was marked out per plans as you see in pic one. I’d read about people putting these too close to one edge and the universal not having clearance. I hope to be OK.

Pic two is setting the tube in place very close to the top of the foam and ensuring as in pic three that the hinge plates will all line up.

I’ve added this entry in case anyone about to do this would like a few pics. Its not very well documented in the plans.

Marking tube placement

Tube fitting

Dry run for level