Did they made a pre-stainless model?Schrade made a model SC505...yours is missing the writing from the one I found on ebay but it is probably from a similar stockman pattern knife .
Schrade SC505 Knife "Inscribed Racing Stockman" 1980's 3-3/4" & Packaging Papers | eBay
It has (3) High Carbon Stainless steel Schrade+ Blades the main blade being inscribed. "SCHRADE RACING SERIES". HIGH CARBON "SCHRADE+" STEEL BLADE. SCHRADE USA. This is a wonderful Racing Series Schrade Knife that will fit right into any collection.www.ebay.com
I'm no expert, I just put the model number into google and it brought a bunch of hits. The ebay ad was the first one.Dud they made a pre-stainless model?
A.G.'s Knife Encyclopedia
A.G. has entries on different knives, blade shapes, handles, patterns, materials, brands, and different makers.agrussell.com