I found this on Gordon Giltrap's site:
(from Colin Welfare » Thu Oct 06, 2011)
"However it was probably 1963 when at a pub in Blackheath Road, Greenwich South-east London, where my friends Bill & his sister Frances McGillivray were playing in their band that, in their break, Gordon did his bit."
So, Frances has a musician brother Bill... a little sleuthing led me to http://www.billmcgillivray.com/index.html so Bill seems to be active still as a guitarist. Not sure about the suggested date of 1963 though, the persons concerned would have been extremely young if my estimates are correct...
Very happy to learn more about the early days of these performers of anyone has memories or additional info.
Regards - Tony