I've not looked at the rules and regs past and present for this so can't comment with any authority on that, but assuming that the CAA exams were passed and then the JAA IR exams, surely the letter that B73 suggests is worth a go.
You seem to be a victim of the system, you want a licence when the system is in a state of flux, you get off you ar5e and get one, Then do the same for an IR. And because the system didn't seem to accomodate people who did it when you did you are to be in my opinion almost punished.
If I remember rightly under the old national system, with the old exams once you had the hours post CPL(H) you would be awarded an ATPL(H) (perhaps with a flight test I can't remember).
Although common sense does not always seem to apply at the CAA, surely if a national ATPL(H) holder can apply for a JAA ATPL(H) what is the difference between him(or her) and helimutt other than the fact that helimutt took his exams more recently than the ATPL holder, and no I am not having a dig at people with great experience who did their exams a long tiime ago, just trying to create some supportive arguments for helimutt to use in his letter if he writes one.
I hope sense prevails in this instance.
Gary