Ken, I couldn't say about the ethics. Lots of period pieces were repaired as well, at least that is what sellers claim.
I am writing because
That is a beautiful weld! I am jealous of your skill with a torch.
The more I learn, the more I believe that to a certain extent swords were a disposable commodity to those who actually used them. It seems most plain-Jane swords are gone, they became new swords, plow shards, and nails. The nails became wire for Damascus gun barrels (at least in the US there are records of nails being welded in to wire and made into shotguns). When I was boy I remember reading in a 1930 or 50's (the swords were $4-20 usd and my grandfather said he couldn't afford them) antique catalog of my grandfather about Janissaries throwing away yataghan sheaths as they got in the way in combat and if they lived they would recover the sheath, if not the sheath didn't matter. I know I destroy thousands of dollars of tools and equipment a year as the cost of doing business so why wouldn't a professional solider do the same? That said, I have read that this pattern was more symbolic than practical, but that could have just been another opinion.