If that new BB is an English thread and the old one and frame are Italian thread…. Italian ones are rare but google it and check!
It’s a Mk2 On-One Scandal, 73mm english thread
I’d also put a lot of oil inside the frame and leave it (on its side) to penetrate overnight before trying again
It’s had several soakings
I had one like that, turned out sitting the frame upright on the floor and standing on the tool was enough to get it moving. Couldn’t budge it by hand or get the tool to stay in like you but that just worked first time.
If the tool ould stay on, I’d have done that a while ago
Only problem is you need an impact driver or know someone who has one.
Good idea, but I don’t have one and don’t know anyone handy who does have one
However, I do have a g-clamp and I’m prepared to use it