I have been unable to find a headrest for KMP625 that looks period correct so I fabricated one. I got the billet clamps from JEGS and then fabricated the rest from polished 6061 aluminum. The clamps are .125 over so I could isolate with rubber. The headrest is has a base of .375 6061 and is then upholstered with a hide that matches the seat. Overall it looks like it came on the car while protecting my valuable brain.
aluminum bits: $100
upholstery: $250
cranial security: priceless
Mark