OEM PCV Valve & Breather Cap, "65" /6

I can't find the appropriate steel/threaded 90* PCV valve or a proper breather cap for my son's "65" Valiant. It has a 225 /6.

It blows oil out of the breather cap @ maderate hi-way speeds.(there is hardly any fiber wool left in it).

The engine runs smooth W/lots of power. The plugs look perfect.

Although the PCV valve "rattles" it does not seem to be pulling much vacume @ higher engine speeds.

I don't think the problem is blow-by & replacing the PCV valve & breather seem to be the logical 1st step.

Would a copmpression test be difinitve?

What would be the average cranking compression?