Identify this unicycle

This time with better (in-focus) pictures. Some of these are in other posts.

Full view of bottom portion
Closeup of crown on frame
Closeup of bearings/cranks (note that that weird cotter pin is simply supported by 4 big washers)
Closeup of hub and broken spokes

I don’t have a picture of the original seat, but it was savage-like with blue and white fabric (blue down the middle, white on the sides), and the original tire was blue with white walls.

It would be good to know what kind this is, but even more important, what kinds of parts are compatible. Would it take Miyata bearings, for example? There’s not really much I can upgrade without upgrading the whole uni, though I may do a full wheel upgrade and keep it as a strictly freestyle uni.

One more question, what size wheel do you think this uni could handle? I just measured, and there is a 3-1/2" gap between the surface of the tire and the bottom of the frame. Another measurement shows 13-1/16" from the axle center to the bottom of the frame. My guess is 24" wheel max. It would be cool to fit a 26", though.

Does nobody know what this is? Or are all the gurus out unicycling instead of checking the forums like they’re supposed to be doing all day?

The seat sounds like the one on my old Oxford but the chrome finish on the entire frame and the bearing assemblies tell me otherwise. The Oxfords did have cottered cranks like the ones on yours.