It is possible that Gibson may have painted the Headstock but to get a quality finish you will want to apply a thin veneer. Ebony would be more expensive than Rosewood, but nothing stops you dyeing the rosewood black before attaching it to the headstock. The reason for the 'skunk' stripe on Fender guitars was to seal the channel that they cut to insert the truss rod.
The Gibson Super 400 was first sold in 1934 and named for its $400 price.
The Super 400 was the largest guitar that the Gibson produced. Until 1939, it had a hand-engraved tailpiece and a hand-engraved finger rest support. During the very early production stock the truss rod cover had engraved "L5 Super"; on later guitars this was changed to "Super 400".
In 1939 the guitar was changed. The upper bout was enlarged, and the hand-engraved tailpiece was replaced with the one fitted to the current Super 400s. The f-holes were enlarged, and a cutaway option was available. This was called the Super 400P (for Premiere), later changed to C for Cutaway.
During the 1950s, Gibson released the Super 400 CES. This had a slightly thicker top to reduce feedback, two P-90 pickups, and individual tone and volume controls, along with a three-way toggle switch. Later the P-90 pickups were replaced with Alnico V pickups, then in 1957, humbucking pickups.