Intermittent crankcase pressure issues

Everything was brand new and freshly machined. It's right around 700 miles at the moment. I used Royal Purple break-in oil and that's what's still in it now. PCV and breather both are baffled but it's an aftermarket breather not hooked up to anything.
'Freshly machined' as in re-bored for new oversize pistons? Moly top ring set or ???? Chrome rings are long/difficult to seat... Got a ring set PN?