Welcome to the Pentax Forums!
This sort of combination is not unusual on eBay. Such cameras are usually billed as "extremely rare special edition red emblem" or something similar. Most likely, the original thin pebble-grain black covering was spoiled by moisture or mold and has been replaced with brown leather from someplace like
Aki-Asahi (great people to do business with). Changing the emblem to red is easily done with a lacquer pencil or pen.
In the outside chance that the trim is genuine from the factory, it would indeed be rare. I have never seen or heard of such a thing.
Steve
(...I have a Spotmatic that was in very rough condition when I bought it and which now sports a very nice lizard-pattern leather cover in deep red...
LINK...)