7a 20v problems

[8690q]

Hi,

My 80 20v avant is sounding poorly. It was going well then suddenly it's sounding rough and driving with little power. I say it was going well but it has been using oil and smelling a bit after a good hiding lately.
A couple of years ago I had a camshaft snap in this engine giving nearly the same symptoms as now. I checked the compression and it was down at near 0 on cylinder 2 which was what happened when the camshaft snapped except low compression was on the number 5 cylinder that time.
I've got it stripped down and the camshaft is still in one piece. Cylinder 2 valves are oily and dirty when viewed throught he intake ports.
Does this sound like a head or block problem as I'm reluctant to strip it any further till I know if I can get a head gasket as sourcing one was the biggest holdup last time.
Is an NG engine gasket the same as a 20v 7a as that would be handy seeing as Andy10v has offered me one if I need it.