Can anybody tell me what the specifications for my 1982 S3 Safari steering column are - I think it's 36 spline but how may mm is the shaft (I have seen it described as 17mm and 16mm) and what TPI?

I have got myself a good looking 17" steering wheel, but I need to find a steering boss and would like to see whether an old Mini boss - or something else from that period - would fit.

thanks! Justin