Behind the spring that's hanging down off the throttle linkage in your picture, there's a plugged port. The oil pressure gauge attaches there. If you choose to install an oil filter, the supply line to the filter attaches at the same spot, by using a T fitting. To the lower left of the sheet metal oil distributor plate, there's another fitting for the oil filter return line.
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
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