[oil pan 4]

Same as any carbureted engine.
I was thinking a thermostatic warm air intake, a big cyclone type air cleaner.
A tune up so the engine runs not too rich and maybe just a little lean. I have found running rich can just about cut fuel economy in half and a slightly lean tune can increase fuel economy by 10% and a nearly too lean tune can improve it 20%.
Then on the generator side add some power monitoring gear.
The big one see if I can run it at 50Hz.

First things I need to do is inspect the wiring.
If I want to pull over 50 amps out of this generator it needs to have 6 gauge minimum, looks like it has 6 or 8 gauge. It should have 4 gauge.
Then devise a way to get all 72 amps out of it.
Remove the neutral-ground bond and put it on a switch so I can go between standalone and building tie in mode.

Then maybe add a provision to pump out the fuel so it doesn't get stale.

I'm thinking I might redo the exhaust so it's quieter and blows the nasty carbon monoxide straight up instead of discharging horizontally.

EDIT:
After taking the cover off the main generator wires appear to be 10 gauge. The main obstacle to just replacing the wires is a current sensing transformer just big enough to fit the 10 gauge wires through.
I don't know if the current transformer is part of an over load protection system or line drop compensation voltage booster.
But it's still pretty simple compared to what I'm used to working on.