ISO Shimano Ultegra (or Dura Ace) R.H. side STI brake / shifter (9 or 10 speed)

I know this belongs on the marketplace forum, so apologies in advance.

Does anyone here have (or know of) one of these I could purchase ? Mine sticks and doesn't shift right. I was all set to buy one from a co-worker; but they brought it to

work and it was the left (front derauiller) and I need the right (rear derauiller).

thanks in advance

DB