Man that's something. I never know that they made a 'manual oiler only' version of these saws by omitting the fitting on the crankcase, the pressure line, the connector, and the duckbill.................and fitting that stupid 'primer' type fuel cap on the oil tank.
I think you just need to get the crankcase fitting (or source something similar from some place like McMaster-Karr), drill and tap your crankcase for that fitting (if it doesn't already have a tapped hole with a plug in it), drill a second hole in your oil tank, run a line from your new fitting into the oil tank, and put a length of brass tube (or the bronze 'connector') and a duckbill on the end of that line inside the tank.