I like!

I once finished up an L-4 restoration. The primary reference document was the WWII Field Assembly Manual, the same sort of book the crew chief is using in this video. Amazing detail...every washer and cotter key, how to rig, the works, all with very basic tools.

Trivia; there is only one easily spotted difference between a civilian J-3 fuselage frame and the military L-4 frame...two very short lengths of .375" .058 tubing welded on top of the left longeron. They were for field leveling so you could rig the airplane when you took it out of the crates. A pair of identical AN4 bolts were dropped into the sockets, which allowed a standard GI level to sit on the bolt heads and clear the throttle levers.