Frank, it is not a mess if you can't find it on the Internet.
Not everything is scanned-in and posted there freely for your convenience.
Some of the Stovebolt members here have the old books, manuals and pamphlets.

Of the valves listed, the CV-609 is about the only easily obtainable NOS part (mostly from ebay).
The differences in the valves listed is for type fittings (hose, metal pipe, screw-in etc.).
Attachments
PCV 261.jpg (75.87 KB, 42 downloads)


"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."