You speak kick ass english for mostly french. Don't apologize lol
I'd try to find a ZA crank used to have it rebuilt. There's a parts motor on ebay right now.
The bushing can be sanded down, it really doesn't matter as long as the bell spins free but also not loose, and the threads can be tapped the next size down on the flywheel end, as long as it applies enough pressure it doesn't matter.
If you've got damage from hammering, it probably needs to be trued anyway, so have a new rod pressed in while you're at it.
Just a tip - a hammer is not a tool to be used on a crankshaft, unless you're trying to align it and have centerpoints and dial gauges.