BCS plastic bushings

[Big wheels are better]

I have a BCS 735 with a 8hp Honda GX240 replacement engine. I bought it with attachments from a small engine shop in western Washington state. They got it in trade for repairs. It had been sitting in the weather and I have no idea how long, or if it was near saltwater.

I’m in the process of reviving it and have some questions/observations.

1. The sulky wheel hubs don’t have bearings. They have bushings that it think are plastic.
2. The rotary mower deck (40 inch? 38 inch?) steering spindles have plastic bushings.
3. The rotary mower deck wheels don’t have bearings or bushings (aside from DIY aluminum).

Is all of that plastic normal? It seems out of place on such an otherwise stout machine. Any known sources for direct replacement upgrades to bearings?