Wow, so many Kaiser-types suggesting answers! Thanks so much.
Every manual and parts list (from the KFOCI Handbook and the repair manual) simply describe it as a 'special hubcap', but do not describe how it is 'special' or show a detailed picture.
I am attaching a picture of my Continental Kit, I thought for sure it is a Kaiser product (is it indeed Kaiser?). The special hubcap must have a cut out to accommodate the black support bracket. In addition, does anyone know how a hubcap could fit with the inner (rusty) disk?