My bathroom remodel was gaining momentum, and I ran into another snag. I was thinking about how to best get my new subfloor around the existing toilet flange when I noticed a couple problems with the closet bend.

The bend appears to be lead, and it looks like the flange is brass. The flange seems to be soldered to the bend. The first issue is that a large crack has developed in the lead directly beneath the flange. It goes about a quarter of the way around the circumference of the pipe. The second issue is that there is a bit of rust where the bend meets the hub of the cast iron stack, and there are water stains on the wood beneath it.

Considering both issues, I figured my best bet in tackling this myself would be to follow Terry's suggestion in the following thread - securing a new bend and flange in the old hub using a rubber donut:

However, I'm wondering if there's anything special I need to do to deal with the corrosion on the hub. It doesn't appear to be extensive, but I think I need to do something about it.

Any suggestions on dealing with it, or perhaps other approaches I could take in perhaps repairing what I have in place now?