I recently bought a 14" projector lens from an old magic lantern cheap off ebay, it was a bit banged up and dirty, anyway...

I managed to take it apart and clean it up, the brass cleaned nicely and except for a few stubborn marks looks good, the glass (which I expected to be a bit of a horror show) also came out spotless and except for a couple of chips near the edge on the rear elements was usable.

So I was happy, until, when tightening the ring on the rear elements there was a crack, crack went the element, and in half, broke clean in half.
Now I have a lens with 2 good elements and a decent body, but one, one that's now 2.

So is it worth trying to replace it?
Fix it?
Sell it?

Use it as a door stop?