Peter
It is fairly easy to identify the differant heads, the Vintage head had three studs on the front one each side toward the outer edge & one at the lower centre at the bottom of the water outlet they also had 18mm plugs the water pump was mounted on the front & driven by the camshaft.
The PVT had four studs dispersed around the water outlet with the water pump driven by the crankshaft via 'V' belt also 18mm plugs.
The Post War heads had two studs, one each side of the water outlet with 14mm plugs, it should be noted that some of the ACE heads had a lower combustion chamber (smaller Volume).
There is one other variable which occured in that there was a bridge piece for the head studs at four positions adjacent to the cam bearing stands to allow oil to pass to drain these heads requires longer head studs, unfortunately this section does have a habit of bending under load, also it allows oil to seep down the clearance hole to the gasket!Not sure when this change occurred?
I hope this gives you the info you need.
Robin