Trimmed all, all OK. Buttons work fine at this point. Trimmed trailing edge to my template.
Spend some more time playing with baffling, and gaining some understanding. Remain baffled how you replicate something made of metal. I make templates, I measure, I mark, I cut. The result does not resemble the template, or the part it came off. Hmmmmmmm. I'm not taking any pictures yet, it is too embarassing...
Remove cowlings and set on the ground with spacers between the leading edges and buttons/hinge pins in place. Tape trailing edges together. Balance on the engine stand, then notice I haven't prep sanded or taped the join. Give up.