Even a Lockheed Part No. would be nice, to aid me in my search.
I've already tried:-
http://www.speedyspares.co.uk - who didn't have one.
http://www.sunbeam-alpine.co.uk - who unfortunately supplied me with the wrong one!
The one I need has no push rod attached. The linkage to the clutch pedal is a long rectangular block with a hole in it.
In my parts catalogue it says either Part No. 1217950 (from B3101201 to intro.) or Part No. 1223548 (fitted from B3105356).
So I'm not 100% sure which one would be for mine. My chassis begins B312.
If anyone is looking for a new old stock one, that's been machine, then hand polished and then clear coated.
I have one for a Mk1 Humber Sceptre, with new copper piping to the slave cylinder
and one for a Humber Sceptre Mk3 (I think, it has the attached push rod with a ball socket attached to the clutch master)

Thanks in advance.