This Tilley X246A was border line dished out but I ignored the general advice, pushed it back into shape, with some force and soldered it to the hilt. The solder stretches down to the lip on the rim so for it to fail it would have to push that out now too. I reckon it's sound and I didn't want to lose this X246A as I already lost its bail clips during earlier fettling. The small cavity in the solder is actually sealed. Technically what do experts think, other than reiterating the standard advice of course.
As one who has recently removed and replaced the bottom of a TL14 tank I reckon you have done a neat job. Personally I would have removed the base first as when the tank has been so over pressured, the likelihood is that there will be some stress fracturing of the solder seam which can't be seen from the outside. Removal would have allowed you to re-make any fractures or cracks. However, you should test the tank thoroughly by filling the tank with water and pressurising it way above the usual working pressure. OK, the tank may fail, but better it fail with water than fuel. Given you evidently are confident with soldering, you could still remove the base completely and replace it.
As R100 says you didn't see what else was going on. The strongest solder join is the one with the least solder in it. Also the more mating surface there is in the join the stronger it is. Solder itself has little mechanical strength so using is to for a "web" over the join may help seal but will bring much less strength than you might think. This is where soldereing differs from welding. That being said I am sure that your works would have melted the solder in those old joins, and as long as it didn't run out they may now be stronger. I would do the water pressure test as R100 suggested It is a nice example and worthy of the fettle good luck Chris
Not impossible but as you say, not so easy. Personally, as the lamp is not significant historically I would just replace it. It would certainly be the safest option.
