hi bill
neither my 10 nor my 14" have rear caps
they originally came in a wooden box and
have a metal/chrome front cap. my 10" came with both
the 14" was missing the box. i ended up with a plastic
lid of some sort that i use as a cap, its pretty lame.
grimes might be able to make you a top-shelf one
if you have the time/effort to send it to them
when steve was still around, he made me a
cap for a vitax lens that was a work of art, just beautiful.
good luck finding what you need !
john