Good work - and love the Jordan shot! I'll have to try doing that one of these days...
Not sure about the top cover on the nose. You could use putty, but it wouldn't stick very well and would most likely bump off easily. Personally I'd probably try using plastic card of similar thickness, glue it on and simply sand it back.
You could try remolding a new piece, but that's beyond my skills and I can't really comment on how to get started.