I have an old brass closet flange that has become completely separated from a 4" lead bend toilet drain. It appears that the old lead bend's edge was originally ball peen hammered for a friction fit and never soldered. The flange is intact. The edge of the lead bend is also intact and bent over enough to prevent removal of the flange. I guess that the old wax ring somehow made an adequate seal. I am replacing the toilet and would like to improve this situation.

What is the best way to repair this?

I guess that the old wax ring somehow made an adequate seal. I am replacing the toilet and would like to improve this situation.
What is the best way to repair this?
Wiping a lead joint,( between the brass flange and the lead closet bend) is almost a lost art. You might be able to locate a old time plumber, like me, to solder the lead bend to the flange but if this were my call I would make sure the flange was secured to the floor and set the toilet back the way it was using a new wax seal. Rule of thumb sez," Don't attempt to fix something that's working." Good luck, Tom,

Spoke directly to the problem and offered a very practical solution.