Cb450 intake manifolds

[TripleKing]

My son's 71 CB450 had air leaks where the carburetors mounted to the heads. I decided to replace the gaskets. As I was removing the gaskets I see a rubber layer on the face winch faces the heads. Does this come off? I hope so because some of it peeled with the old gasket.

 

[TripleKing]

OK, I see that the rubber is part of the boot. I need new boots as the rubber was damaged. Looking for boots in good condition with the old gaskets removed.

Edit: Just ordered new boots.