Good on you for going anyway D_XZ, and thanks for the report.
Incidentally, you mentioned Kona changing the geometry and I said they didn't at this time, but they did change it between 92 and 93 and then again between 93 and 94, so if you have a 92 or 93 size 19, I wouldn't rule out a 96 size 18 being roughly the same size. The key thing is the top tube, which on the frame you measured should have been 562mm c-c along the tube. I wonder how that compares to your current top tube?
He could well have bought the bike in 1995, as 96 models went on sale from September 95. It probably has a 95 serial number as well - most 96 models do!
I once saw a 96 Kilauea frame fetch over £200, but that was in just about perfect condition and even then it was an exceptionally high price. Normally they don't go much above £100, although I personally would say that is the market under-valuing them. Columbus Cyber is a very good tubeset, and it makes a very good, light weight, all-day cross country frame. The original paint is very good too, especially in full sunlight. There's no way I would have it resprayed.