Nothing a little help from the 1/8" 4 flute carbide endmill can't solve.
All true'd up now. Flipped them over and did the other side in the same way.
clamp clamp mushroom, mushroom.
Front edge lined up.
Injecting Weld-on into the joint.
Clamp another side on and tape it in the corner so it doesn't shift. Not a lot of pressure is required with weld-on, tape and a light weight or clamping pressure is plenty. No gorillas need apply.
Other side, more tape. The strips pull it toward the middle, while another strip holds it to the side. They fight against each other, and put downward pressure on the joint.
Tape down the end cap and clamp it on the sides.
The melted-like appearence of the joint once cured. Weld-on is a solvent-cement, meaning that it softens the surfaces and, as it dries/cures/evaporates/ the now semi-fluid surfaces are permanently joined.
Side 1 all done.