I've had a short bit of experience with one ply Gibson bass. It is currently owned by John Shuffler (brother of George Shuffler of Stanley Brothers fame).
John always played gut strings in his days with the Stanleys (yep, he played with them for a short while too). This was in the early 50's. When Super Nyls came along, they became his string of choice, due to their similarity to gut, with regard to tension along with diminished tuning issues.
At the time I played John's old Gibson, it was strung with the Super Nyls and I was currently adjusted to steels, Helicores to be specific. The bass didn't impress me at that time, but John sounded fine on it, playing his typical Shuffler walking style.
Since I've changed over to guts and Garbos (on 2 different basses) I'd like to try John's bass again. It was found in a barn in Lenoir, NC, about 10-15 miles from me.
John's bass did have the 3-piece neck and had to be refinished due to the years spent in the barn.
Harold Nixon, current bass player for the bluegrass band
The Boxcars, told me of seeing an old Gibson bass in a music store in KY or OH a few years back. It was apparently NOS, complete with hangtags and still for sale. I might need to track that down, though it's probably already gone.
Happy New Year folks!