Morning Blended,
Can't help a lot with the ID of you blue one, its old and american, I'm thinking bolens or simplicity or something along those lines, I'm actually surprised by the chain drive, most of that style mower were trans axle driven.
However it looks like its possibly a peerless diff, which is pretty common and if it needs bearings or seals I reckon you should be fine to just go generic and get them from a bearing place. I doubt you would get oem parts for something that old and american here in Aus.
It will help a bit with the turning but most of that is the lack of steering lock the greenfield's were capable of, a few mods in the steering department will go a long way too.
