The number is indeed the serial number. Yours is the 75th shadow III ever made. Its either made in South Africa or USA. It will say on the blade. Also, ifs its South African, it will have a "Hex" shaped butt cap. If its USA, it will have a "Round" butt cap. BUT, some USA Made One Piece Knives had a "Hex" cap as CRK had some left over when they moved stateside. I have had 3 shadow III's overall. My first CRK was a shadow III. I liked it so much, I bought another for backup. I later bought a single guard shadow III, but recently sold it to a One Piece Collector. They are great knives and very durable. I once chopped though an ironwood tree ( Very Hard Wood ) that was 5" in diameter. It took aprox. an hour, but it did the job. Thats the only knife I had on me at the time. I edc my shadow III all though hunting season.
Check out my CRK timeline in the sticky, there is info that will show you aprox. when your shadow III was made......Enjoy...!!!