Props came in three styles, 3 UJ's (circlip or staked types), 2 UJ's (staked type) plus a centre CV, and then 3 CV's. Your's probably is either a 3 UJ or 2 UJ and 1 CV type. You'll need to check the diameter of the centre bearing. I had a propshaft made up by a specialist from an old 3 UJ staked prop but fitted a later centre bearing with a sleeve fitted to make up the thickness.
Have a look here.
viewtopic.php?f=2&t=25463&hilit=propYou could research and fit an alternative bearing with a bit of alteration.
An automatic OHV single piece prop has the same splines but may be a bit longer, I'm not sure.
I ran a single piece prop for a while when my new 2 piece as getting made up. I found that the single piece prop was OK but it does make the car a bit less comfortable and it adds enough to the unsprung weight to need a couple of extra clicks on my adjustable shock absorbers.
Editor of the VVOC Magazine ReVival
"When you have a Firenza like mine, who needs any Minis?" copyright David Maxwell 1979.