Part of mounting the D window frames in the fuselage involves putting the support tubing in the cargo door. It’s a bit tricky because the skin shape varies as it transitions from back to front and none of the tubing should stand proud and interfere with the outside skin and the inside covering. As a result, there was a LOT of fussing with straight edges, clamps that would fall of right at the wrong time, etc. But, it was finally located, fit and welded. One thing was the cargo door latch...it turned out it was just a teeny bit too long to remove in case it needed repair. Simple solution…make the T-handle removable.