As a young chap I saw a friends father do the following-
heat up the area where the outer rim connects to the inner , on the tube side, with a gas torch. Eventually you will see the rivets start to glow, heat them orange and knock them out with a punch. The inside dish will fall out. Bolt the inner up to a front hub and put the new rim on the inner. Line up the outer rim with a fixed point or dial gauge, check for in-out alignment, and carefully weld up.
I cant remember the issue but it was a requirement to fit a new rim to an old inner dish.
