There is nothing like regular oil changes to extend the working life of an engine.
There is an 84 year old "retired" market gardener up the road who occasioally pops in for some parts.
Being retired he only works 2 acres, single handed.
the first tim I went into his machinary shed, I thought I had gone through a time tunnel.
The newest piece of kit in there was a Jawa industrial engine from 1959 on an open crankcase pressure pump from 1942.
Most of his gear he inherited from his father.
Anyway there were empty 44's everywhere, cut in 1/2 lengthways for sorting and seedling beds, perforated for tumbling dirt from the spuds, supporting tables, being used as water tanks etc,etc,etc.
I thought he must have been a mechanic at some time, but no, the oil drums were all emptied on site.
He goes through 2 to 3 drums per year in total ( six different types of oil ).
Anyway , the 1941 BSA 320cc engine I was there to service, is still on its original bore,hanging off a 6 tyne walk behind rotary hoe he inherited from dad that was more weld than original parts.
I had a thought about it , 3 44s of oil is about $ 1600 down here and you could not service a quarter of the gear he had there for that price.