In reply to Geraldine Taylor:
> ... London Wall has a powerful start and a thin finish where it is normally hard to stop and put gear in.
I've twice held the ropes on LW for friends who were halfway decent sport climbers (both had done a few 8a's). One failed on the start and the other decided he wanted more gear about two moves from the top and pumped out putting it in.
On the other hand, if your fingers fit, you make good use of the rest and you are happy to push for the top above bomber gear, then you have every chance of success.
Judging from his profile, Mark S has ability to spare and it's high time he rounded out his climbing CV with classic testpieces like this.