Thanks, I took a look see, but can't remember what exact model I have - 550-4 but my year says 1974 and theirs begin with 1975...strange?
I may e-mail them, I'll probably get to go to England this next year, and might just pick them up direct and I'm not too proud to carry them on the flight! (hahaha-what a riot that would be-can you imagine the security screeners!)
Thanks again,
Linda