I say 1940 but I don't really know. A friend on the Unofficial Martin Guitar Forum concluded that this was built by Epiphone in 1940 or '41. There were very few of these ever made.
This one popped up on the local Craigslist. I don't think that many people on there knew what it was. Of course, this is no asian made Epiphone. This was made before Gibson purchased the Epiphone brand in 1957. They moved the production of Epiphone branded instruments overseas in the 70s tarnishing the name. The American made Epiphones were very fine instruments.
This Epiphone lived a sordid life. It came to me covered in soot with two stickers and a name carved right in the top. The seller was the nephew of the schizophrenic aunt that owned it (last). The soot and stickers came up fairly easily with some Naptha and elbow grease. The name, "Kelsi" is there to stay. It features an Adirondack Spruce top, Walnut back and sides, and what looks like a very dark Rosewood fingerboard. It has feaux tortoise shell binding and a very nice pearl inlay on the headstock. The tuners have been changed. It still has 4 of the original Bakelite bridge pins.
The FT-50 started showing up in the 1941 but it says that they had Mahogany backs and sides. It also shows a model FT-45 that had Walnut but also white binding. This may have been pre-catalogue before they really nailed down what was what. The label with the model number and serial number is badly torn so we may never know if this was a 45 or 50.
The Epiphone researcher that I spoke with on the forum said that since this was X braced and lacked the metal cover for Epiphone's "thrust rod"then this was probably pre-war. His research indicates that the model line was reduced during the war and this was one that was cut. They start reappearing a couple years later with serial numbers indicating 1945. After that, the FT-50 was cut for good.
He is currently compiling serial numbers, pictures and catalogues into a database so he can offer a better understanding of Epiphone's past. Do you have a guitar like this? Please email me and I will pass the information along to him.