I broke down and bought a bandsaw:
I think this is the same $99 Delta unit that everybody else buys for their RV. I put a 15 TPI blade in it, and it cuts through aluminum like butta. I spent most of my limited evening fiddling around with the 972 little set screw adjustments on it, then used it to cut out these funky looking gussets:
I've got enough finished parts built up now that I can probably do a medium sized batch of fuselage riveting, once I do a medium sized batch of deburring, that is.