My TR2, purchaced in San Jose, Califoirnia in 1955 has that valve cover with those knobs. The oil filler cap is chrome/silver. I never new it was anything special, and I don’t know if it came with the car or was added later. It’s a great thick, flat, and solid cover. It may be the only car I’ve had without a hint of oil seepage from the valve cover and gasket. The car makes up for it with leaks in other places, though.
Steve