I need some clarification on an issue please.
I have trawled previous posts but I am still a bit confused. Please forgive me if this has been covered.
My Dolomite started life as a 1300 non overdrive but has, for many years been a 1500 o/d (among many other changes).
I am fitting a new engine and gearbox as my old one was a bit tired, the new engine is from a 1500 Spitfire.
The new gearbox which has been coupled to my existing bell housing and o/d unit.
I am now putting in a new clutch and here is the issue; I have come to find that the clutch on my old engine is smaller than that on the 1500 spitfire engine (and also the new clutch I have bought too!

The bolts on the old engine are also fatter than than the allen key bolts that held the clutch cover on the Spitfire engine.
Both have the ring gear that fits the 1300 inertia starter... not the pre engaged one.
It seems that the Spitfire Flywheel has a protruding ring on it where the clutch plate bolts fit into it whereas the other one on the engine that has come out is virtually flat.
Is it feasible that the 1500 engine that I have taken out was just running on a Dolomite 1300 clutch and Flywheel?
If so it is lighter and should I just transfer the Flywheel from old to new, getting a new 1300 clutch, what are the implications of either route?
If I stick with the larger clutch and Spitfire set up, does anyone know where you can get a new allen key bolt set for it as one of them is burred.
Head hurts, thanks for reading.
Thanks for your time.