The oil pipe in the center of the rockers is perfectly normal- - - -every 216, 235, and 261 for over 30 years had something similar. There's a small hole under that tent-shaped cover. The rest of the oil goes out the end of the pipe and drains back into the side cover, and from there to the crankcase. On a 216, no oil will flow to the rocker arms until pressure at the main and cam bearings reaches at least 15 PSI. Unless you rev the engine up, you probably won't see much oil at the rockers.

The valve at the thermostat housing is a cutoff valve for a heater hose. If you remove the two bolts above it, there's supposed to be a thermostat under that casting.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!