Thanks The Dream,.
Yes it is of some help. I have heard that if you get an FAA or canadian CPL/Class1 then you can obtain a JAR one on the basis of this and only go through a class 1 renewal rather than the nitial (plus do the CPL exams).
It does seem to be a valid 'back door', but rather an expensive and convoluted one for someone like myselef who just wants to do the odd bit of part-time ppl instructing.
I will investigate this further though.