Thanks David - I've already acquired one of those, on my 410 it goes at top of steering column, it's the UJ nearest the steering box I'm struggling with.
Graham at Classic Bristol has one that's been removed from a car so he's kindly going to count splines, measure etc when he has a moment and then we can see where we go.
It does look a lot like this though...
https://www.sngbarratt.com/English/U...6-8870e4aabfad
Cheers
Andrew