haha, jo anns... I know that place!!
so yeah, I've tried to shave off a little plastic in that same place with my pocket knife... definitely didn't work as well as your method does! so as soon as I get my hands on a disc sander or a dremel, I'll o what you did.

Thanks guys!
The cape is an inexpensive cotton bolt from Jo Ann's.
Cut a semi-circle (yes, you need that much) so that the
fabric edge will form the straight sides of his cape and the
curve of the semicircle forms the bottom. Fold in half and cut
a little V for his neck. Then fold inwards like a paper airplane
before glueing in place... that will help create the double folds
once the glue sets. The cloth I get is pretty good to work with
too.. never needed to add any wires or anything.
The red paint is gloss red Testors, should be easy to find.
The crotch fix:
I used my disc sander mainly to grind it down. Then I used
a little apoxie sculpt to cover over any open gap areas and repainted
a bit. Here's an image of just how much crotch and thigh I
had to cut away, but it all still works well:
Go low vs deep and you should be ok.

wow this is sick man!!! I'd like to know how you did it though, too! so I can try it myself maybe.

lovin the cape man, this custom would be a good christopher reeve superman if you made a custom head, but it still looks kick-@$$

nice fix!