Most of the mowing around my place is done with a 40's Farmall A.
I've used various old tractors (English Fordson, Farmall A, Field Marshall) to power a buzz saw by flat belt. I've cut a fair amount of firewood using the buzz saw.
Done plowing and disking at my place with these tractors, Rumely Oilpull 25-45R, Oliver 99, Case 900.