Today I got started on final assembly. In the first photo I've finished pre-tinning the top and bottom ribs with Hi-Force 44 solder and acid flux and am just starting to pre-tin the barrels.

Once that was finished, and everything had cooled down, I took the three pieces to the laundry tubs and scrubbed them well with HOT water and a strong cleaner. This is absolutely necessary in order to get rid of the acid flux before final assembly. Otherwise. you'll have the acid causing rust in all of those hidden places.I then laid them in front of an old hair dryer, set on high, and went to watch the Olympics for half an hour while everything got good and hot and dried all the residual water. Then I painted all of the mating surfaces with a liquid ROSIN flux and clamped it all together. The next two photos show things set up in my Rube-Goldberg jig, Coleman stove in place, and ready for heat and solder.