Unlike my D2 that came with a plastic Christmas tree that got stuck in the valve cover, which needed the top plenum and valve cover off to remove, the ‘97 D1 that I am driving now came with just two simple hoses, one from each valve cover connecting to the plenum. A quick removal, spray with CRC throttle body cleaner, and clean the orifices if dirty, and re-install. This little piece of preventive maintenance is very easy to do, and it doesn’t hurt to check every 6 months or so. Once the hoses are hard to squeeze, one could simply replace them.

Not sure, but I think there may be benefits in having a pcv on each side of the engine, instead of just one?

 

there should be a plastic christmas tree on the passenger side where the hose fits into the valve cover in a '97. Yours might simply be missing.

Your point remains spot on. A regular shot of brake cleaner on that plastic tree goes a long way to keeping your engine happy.