I cannot speak for the toro, not dealt with them.
The Ransomes is a motor triple, all mechanical drive through belts from engine to transmission through varispeed pulleys.
A good solid machine, however the faults are if you travel with the cylinders half raised a lot you will shear the rollpins in the lift levers , not a big problem but another job.
I don’t know if parts are still available for these machines, but back in the eighties when I was working on them parts were expensive, ie traction belt £80 , the double U/J drives to the left or right front cylinders was very expensive at the time I think£200 , this coupling is less than a foot long, (even the manager queried that one) .
If you are buying one make sure the cutting cylinders are not worn out, ( down to the internal supports) and see what condition the blades are in, not bent ,chipped or other damage.
The machines were fairly reliable, we worked them nearly everyday over the cutting season for about 7 years each , though they had a full service and sharpen etc each winter.
The Mag engine was very good, we never had one in pieces! Engine Faults were always the stuff that bolts onto the engine!
Most repairs are straight forward as it is all mechanical, only electric is the starter and dynamo and lights.
No hydraulics to be troublesome and everything else shafts rods and linkages! Be aware cylinders mowers need much more attention than rotary.