> "OEM screws are plain steel and  just painted black"

Not long ago I bought new fasteners from a VW Dealer.  The black plastic
and the screws, too.  The screws had that "Goldish' finish ... no paint.

The new black plastic came with push pins which I "Pushed out" and
discarded as I prefer using the screws.

The only rusty screws I had previously were ones that were not original.

Mike
'84 GL 7 pass
'84 GL Westy
'85 GL Westy