Due to other priorities, I didn’t have much time to work on the plane. However, I was able to fabricate a pair of pins for the rear spars. These consist of a pin made from a 1/4” bolt, a handle made from some scrap 3/8” x .049 wall 4130 steel tube, and a vinyl cover made from McMaster-Carr # 40005K21.
The pin is tack welded into a ¼” hole near the end of the tube, and the cover is trimmed to length, then slipped over the tube.
The handles of both the front and rear spar pins will be locked in position by McMaster-Carr Black Plastic Tool holders # 1171A69, mounted to the fuselage structure.