I'm attempting to build a .400 Jeffery on the same type action you used ,mine is a 1957 -49 Brno , I have about the same tools you used as well , I would like to ask you a couple questions if you don't mind ,
Did you turn the chamber end of the barrels to 1 inch before you cut the relief ?
Did you have any trouble getting the hook pin out of the action ?
Is 45 % silver ok for the brazing , ? I have a forge but I think I'm going to build a ring torch.
Thanks again for taking the time to post the information and pictures of your rifle , it motivated me to get started again on my project.