For what it's worth, my 84 Westy came with the cheap hubcaps, probably from
one of the *Marts.  They look OK to me but when I took my van to the
mechanic and complained about squealing brakes (I'd had the brakes done
recently), they told me the cheap caps were causing a lot of brake dust to
accumulate, hence the squealing.  They blew out the dust and it was better
after that, but now the squealing has returned.  This could, of course, be
horse poopie but I thought I'd add it to the thread.