I'm glad to of some help in this area of research! Yes, I read from time to time in the past of books that have mentioned Canadians serving in the British Armed Forces, during the Imperial years etc,.
Here's a few names I've come across that served in the British Army
1 William Gun Chong (Agent #50 ) British Army Aid Group-MI9. http://www.ccmms.ca/vets/ccmbchong.asp
(Pte Noble Goulding Sproule,haled from Port Credit,Ontario,Canada. Joined the Manchester Regiment, at age 17 yrs old.
4http://users.telenet.be/ppa/ check out the name base on this site and their are 2 men that are born in Canada
that joined this unit.*
I hope this helps you out in this area, Ken??