Hi, I have an nice motobecane frame, but the BB is french-threaded, and the drive-side is also seized on there. I've tried the bike-in-a-bench-vise trick, and thought briefly about welding a big nut on to get a better grip with a big-ass-wrench™ and a few other hairbrained schemes came to mind, but I've yet to try anything that might ruin the bike.
I'm thinking that it might just be easier to buy a new BB shell with standard threading and then I get a new sealed cartridge BB for 30 bucks or whatever and still end up coming out ahead instead of buying a Phil's.
I'm proficient with a torch, I worked for a while brazing lots of copper pipes with silver alloy, and got pretty good at it... but I'm a bit unsure about to go about removing and replacing a BB without having everything else get out of whack on the bike. I imagine some sort of jig is going to be involved, but I'm having a time picturing exactly how to do this.
I'd like to get more into framebuilding anyway, so if there's plans for building a jig or whatever, I don't mind doing that as I'd likely end up using it one day.