Not sure where you are at with this, but, this just showed up on my facebook Midget group:
I’ve had serious issues with my ‘67 Midget smoking intermittently and using oil. Recently we drove 100 miles and used up 1.5 quarts of oil. However I have terrific compression and it doesn’t smoke when it’s cold.
I figured I would look at the PCV and see if there was any evidence of a bad diaphragm. Upon opening the unit, I could see that oil had clearly gone through it and was being drawn into the intake manifold. I examined the rubber, the piston/needle and the spring and they seemed fine.
It was only when I started to reassemble the pieces that I realized that centering the piston/needle was not so easy and that if it wasn’t perfectly centered when the diaphragm and lid were put back on - it would not seat properly - and the PCV would therefore suck oil at high vacuum.
After several attempts - I got the piston/needle centered with the rubber diaphragm in place and the top set in place with the spring clip.
Drove 95 miles on the interstate over the last two days - no smoke and not a drop of oil used.
Pretty happy with the easy fix for a problem that has dogged my car for several years.