I'd be cleaning it up with brass brush and kerosene, the cooling fins etc. No adjustments possible. The heat sensitive clutch element is the spring steel piece.

And maybe ask yourself about engine maintenance when the fan is removed. General scrubbing of engine, torquing of loose bolts, belts, hoses and replacement of rusty ring clamps, garden hose pressure wash the radiator core - that sort of thing.

On the diesel I like to put old bicycle tire chafing gear around wires and hoses that might rub against something when the engine rattles, securing them with cable ties too.

There are also all sorts of alloy goodies like vacuum pump casing, A/C bracket, power steering bracket, banjo bolt channel tubes, cyl head and lower engine casing that are just plain fun to look at when they are cleaned up.