I did some more investigating and puzzling over how to attack the poor fit of the forward fuselage structure and the canopy structure. here you can see that the canopy structure is actually about 3/64" too wide on each side.

I decided that I was going to need to remove the rivets attaching the canopy pivot arms. These holes will probably need to be filled with weld, filed smooth, then re-drilled.

In order to figure out the arrangement of structure and skins, I decided that I needed to nail down the position of the canopy structure. This means I need to rivet the popup arms together. Before doing that riveting, the parts need primed, and before they can be primed, they needed scotch-brited to remove all the oxide. All cleaned up in this photo.

Primed the parts.