Thats the 4 tines per rotor, 4 rotor machine? Neighbours have one. I've worked on it a few times.
The rims rusted out. Couldn't see inside of the dust shield but they rusted right off the hubs.
Its all held together with roll pins. Get a selection of them as you'll need them.
Grease it, the sheet metal cups under the rotor bushings rusted out on theirs as it wasn't greased enough. Seems like a tough machine, very few problems with it besides rust. It did break a roll pin and jump time at the end of last year, have to retime it this spring. I've never seen a manual for it but everything comes apart pretty straight forward.