Hello Mark -
I am fortunate to still have the original 5-3/4" Tung-Sol sealed-beam headlights on my 300C - they cross-reference to part number H5001 (high beam) and H5006 (hi-lo beam). I believe the "H" means "halogen", which would not have been applicable in 1957.
Other General Electric numbers such as 4000 for the Hi beams and 4001 for the Hi/Lo beams are also found. I can't get to the backside of my installed headlights to see if any original numbers are still visible. There are numerous 5-3/4" conversions that
use superior H4 and H1 bulbs if you are more concerned with lighting effectiveness than with absolute originality.
Ray Melton Las Cruces, NM 1957 300C cvt
Can some one please tell me what low beam and high beam head lamps are used on the 300C.
Thank you,
Mark Schueller
300C, 300F