I am not the expert in this area, mostly just X-spurt. But your 813 / (1993) is from the early 90's promotion Buck did called the Workman TM series. They produced three models for a couple of years and then dropped the line. The one blade is a 811, a two blade is 812, yours is the 3 blade 813. The / after the model number dates its blade stamped in 1993. The Workman series promotion was aimed at knives for the working guys, expecially for box, carpet and vinyl cutting. The were produced by Buck and have the standard Buck 420HC steel in there blades. Most had the Workman symbol and letters on the blade, but you will find some without the printing and some where with a light application of steel wool the owner removed the ink. Value is usually not extremely high but guys with Buck collections sometimes pay a good price for unused one with box.
A few were special runs for companies with special printing on the blade, I have a burgandy colored handle with "Grainger" printed on the main blade. I know there is one guy that posts over on another forum that talks like he 'collects' these but his contact information slips my mind.....They are a rough and tuff knife, that was made in the Buck factory. Do you know about Bucks post 85 blade date stampings.?
Thanks for all the great infiomation. You hit the nail on the head when you said it was a rough tough knife. As for the date stamping I do know about it and in fact I have a little chart but it's ten years old. I have a small number of Buck knives in my collection mostly Pre 1985. Buck was the only knife I would carry and use when I was in my 20's over 30 years ago. In fact I always thought they blew Case away for durabilty. I have since learned to appreciate Case as a collectable but I carry a Buck 112 and camp with a 119. Old habits are hard to quit.
Once again thanks for the info,