Great work Paul.
How did you make the flange on the top?
I used a couple of machined "nuts" on a threaded 3/8-24tpi rod. One nut was machined to fit into the
Bottom of the tube to be flared. This was made from 1 inch 12l14 steel a portion was turned down to fit
Into the tube. The other nut was turned with a 45 degree taper with a short section turned to fit into the tube ahead of the tapered portion of the nut. Both nuts were threaded to fit the rod. The tube was slightly chamfered at the end to be flared. By placing the nuts at each end of the tube and turning the top nut with a large wrench while the bottom nut was held in a vise the flared end was produced.
Tube