I've always had a small problem with these since they were produced.
The plaque states that the gun is "one of fifty originals found and preserved in this way". But, look at the patent drawing, it shows a Nelspot, but the gun in the display is a "007" version of the Nelspot which has all the upgrades which were done post-1983, the barrel bushing, and the magazine cross-bolt. The Nelspot was modified in this way for the NSG/paintball market, but remained the standard for the Forestry/Agriculture industry too.
Technically, it's not the same as the markers used in the first game of paintball. I don't recall who put these things together, but I do remember that it was around 1992, they were expensive, and many were handed out to long-time industry leaders, the rest were sold off to those who could afford it.
It's a nice presentation regardless, and would be a fine centerpiece to any collection, even if they're only 95% accurate.
You have a great collection there.