Today I fitted the chimney right angle piece, drilled and soldered on its flange, and drilled the end plate to accept the flange. Then I CNC drilled the big bronze end plate to accept the flange.
Then I carefully positioned the bronze end plate, the firebox and the firetube, and silver soldered them together.
Next, the inspection hatch will be soldered to fill the rectangular hole.
Then the main bronze flange will be permanently attached to the boiler shell. I intend to silver solder it, but considering bronze brazing.