The only Massey tractors I've messed with were Model 65's. I have one with a 4-cylinder Perkins diesel motor. Runs nice, about 50 HP. It used to have a gas-fired Continental motor that was a piece of crap. I could not keep that thing running, so I bought a junkyard diesel motor and converted the tractor to diesel.

I borrowed a Massey 65 built in the late 50's with essentially the same Perkins motor, except it had a funky pre-combustion chamber and glow plugs.

One thing that seems odd about both of my farm tractors is that they don't have glowplugs. So long as the air temp is 40 F or above, they just fire right up. Below that temp you need to crank it a few times or plug in the block heater for a while.