Hi, Nik.
The two girls I saw at the London Retreat were Louise (retired) and Alex (working there today). Both were great but you are talking £200 per hour, there.
Sadie-Strumpet used to be Lisa at London Retreat and is £150 per hour. If she could see you today (doesn't work at weekends) she would be a good option. Piccadilly Circus is her location.
Good luck,
C