Sticky Pipes!
I just started using Aves Apoxy Sculpt. It is a thick epoxy Modeling Compound, that can fill Large Gaps and be Shaped.
After mixing the Apoxy, I rolled it into "Snakes". I stretched the Snakes to fill the grooves in the backside of the Headers.
Next I cut 2 lengths of Aluminum tubing to fit over the ends of the Headers.
More Coming...