It looks like a well made machine. The frame for the tailwheel looks a bit unique. I originally though it was a FMC or early Servis, but it just does not look quite right. There where/are so many companies that make or market mowers anymore it might be hard to track down just exactly who made it. However the gearbox and blades where probably "off the shelf items". You should be able to take the blades and find some that are identical to them on the shelf at a equipment dealer. You might have to hit a couple of places to find a match though. You should also most likely replace the blade bolts at the same time. The seal would basically have to be done the same way. Pull it out(carefully) and try to crossmatch it. An independent bearing supply or someplace like Napa(if they have a good parts guy) could probably match it up of your local tractor place was not much help.