Probably an old hat to you, but Vekke designed smooth hubcaps for trucks/trailers some 11 years ago.
this is his thread:
https://ecomodder.com/forum/showthre...cks-16478.html
and these YouTube videos seem to be most informative:
Covers are made of 3mm ABS sheet, iirc. The design is pretty straighforward, so you should be able to duplicate it, unless you are hopeless with jigsaw. I would try it for sure, if I were in youe shoes. smooth hubcaps are how much? 3 %?