OK, TT wins the biscuit
I just took my nosecone off, still could not see a number. Got out the toothbrush (don't worry it was the wife's not mine

) and white spirit and gave it a good scrub. Could just about make out 1/2 of one digit so got out the drill and wire brush, there was the number right where TT said it should be. Just under the head and slightly to the right of where the dizzy lives. Thank God it's the right one too

Panic over, thanks guys.
Enoch