valve stem oil seals?

[cab43]

Hi all.
I've just discovered that my mm has killed it's head gasket, so started stripping the head down and found it still has the old 'o' ring type valve stem oil seals.
I was told that the car had an unleaded head fitted years ago, but I thought these heads came with the later top hat style seals.
Any idea how I can tell what head I actually have?
Also can I fit the later seals to a leaded head (if thats what i have) it has smooth valve stems?
Oh and I'm short on time so don't have time to order from the usual suspects so does anybody know what other cars these newer seals fitted so I can ask my local parts guy.

Thanks.

Paul.