If you have a Shimano Dura-Ace 7900 rear derailleur in good condition that you would sell for less than £40 posted (condition dependent re: price), please get in touch. My understanding is that 7900 shifters will work with a 7800 rear derailleur as well (unlike the comparable FDs), so a 7800 RD in good condition might also do the trick..
Thanks for looking.
Thanks for looking.