Supro valco serial number dating
It's possible that it wasn't the original fretboard.
While the markings match the 1958 one above, it has different markings to the other 1956 model that I bought later (see below).
I sold this red 1956 one in October 2009 because I had another Supro (a 1954 Supro Comet), and I wanted to diversify a bit.
Soon after that I bought a 1960 Fender, a Gretsch (also made by Valco) and a late '40s Rickenbacher. It was pretty much identical except for the fingerboard, as you can see from the photos.
It was obviously very old (discoloured in places and also stuck to some surfaces).
The catalogue below says this model has a "sparkling transparent third dimensional fingerboard backed with gleaming gold".
They embraced a very ornate, Art Deco and early Moderne look to many of their guitars, with beautiful ornate Egyptian influenced motifs for position markers and spare two tone streamline body designs that recall the designs of concept cars of the day.
There is a video on You Tube in which he talks about his slide guitars, including this one. A company named Lollar now produces a substitute for these pickups.My first '56 has the cream fingerboard in the photos (see photo on the right although it's transparent in the photo above), whereas the second one has a black board with metallic position markers, shown below.When I removed the board there was a sheet of what looked like aluminium foil, under the perspex.Certainly in the 1954 catalogue that I have, the Supreme is described as "glossy rich brown washable plastic finish".Note the fairly ornate tuner buttons on the 1956 models - these are the original Kluson tuners and were in amazing condition on both of my '56 models. Also note the original screw-on cable connection in the photo below.