[BruceLambo]

Matt, I sent you a private message, but it doesnt seem to have gone. Anyway, how about just having the pilot end re-sleeved? Have a competent machine shop skim down the scored end, and have a hardened sleeve slipped on. Thats one idea. I think you might have an alignment problem with the box/engine for you to be looking for your 3rd shaft. Making another one wont fix an alignment issue.
But if you do want to change to another clutch plate, then the idea of a new shaft is easy. You will need a competent machine shop to make it for you and to have the splines cut to suit a different plate. Make very sure though, they use the 'right' steel, and use the 'right' heat treatment. But if the bearing issue is fixed, then there is nothing really to be gained from having a new shaft done just for a different plate.