Mine broke at the bend where the little tab sticks out for
the slot. There was just enough left to put back in the
slot. Now it snaps shut with authority. It broke because
I kept trying to bend tesion back into it.

There was someone on the PY forum who was having
a heck of a time putting a new spring on. I think he said
he kept screwing up the fuel door trying to get the old
one off, but he had a couple extra doors. I have never
tried removing one. I think he might have decided on
using a magnet.

looks like a rubber grommet/spacer/plug in the pic...
i thought i remembered there being one.