It would be very strange to have a Columbus fork on a Tange #1 frame. Are you sure it's original. I can't get a good look at the embossing on the crown. Regardless, you can check inside the bottom of the forks steering column for Columbus's patented five spiral ridges.
The fame is very rough and very small. The size limits the market and the the new owner would have to factor the price of a repaint into it. Personally, I think there is little value. However, there may be something in the fork, if it turns to be Columbus but it all depends on the length of the steering column. It appears to have a threadless adapter. If this is true and it is a Columbus fork, the value may be virtually nil, as there may be virtually no unbutted steerer length to accept a safe length of quill stem.