If you can't buy the parts you need! well improvise with what's on hand.
Known history of this 16 tells us the power plant hasn't been apart for the last 40 odd years, this repair could be even older.
Obviously a flogged out pin fit in the fly wheel, remedy! 15thou over size wrist pins, out of what, I don't know, bushes reamed to match, all still like new today!!
They have a tell-tail clamp screw cutout. Was the flywheel reamed for the wrist pin? If so, the flywheel won't take a standard pin now. T wrist pins are ~.740. The stock flywheel bore is ~.680 with a step to ~.687.
If ya gotta, ya gotta, I guess.