I first see the #881 listed in my 1953 catalogs though, no doubt, this 4" three bladed Premium Stock knife traces its roots to earlier Schrade Cutlery Company patterns. The base #881 with stagged bone covers is listed along with the #881Y with Maize (yellow) plastic covers from the 1954 Schrade Walden listing. The old SCC number referenced in the 1953 ans 1954 catalogs is #8815, and it is called Premium Stock Knife, Texas Pattern, with the classic clip, sheepfoot, and spey blades, nickle silver shield and bolsters, brass linings, large blade polished one side. By 1961, the stagged bone of the 881 had been replaced by Unbreakable Staglon.
The last catalog appearance for these two patterns was in 1986, when they were dropped from the ever-thinning open stock line. In that last year of listing, slightly less than 6,000 each of the 881 and 881Y were shipped. Other than the remaining 3,500 881Y shipped in 1987, only a few warranty replacements were shipped the next few years. In 1991 although it did not appear in the regular catalog, Schrade made a one year only run of about 20,000 of the 881, shipping 18,000. The remaining 1,800 knives shipped the next year. There was not a second run of the 881Y pattern that I could find, so its last year of production was 1987.
Your knife was made between 1973 (when Schrade-Walden became Schrade) and 1987.
Codger