Here is what I have found while paging through Camillus Catalogs of the early 1990s:
A full page of the 'Woodcraft line', in the 1990 catalog, including the 886 with the Silver Sword tang stamping. Oddly, these knives have no pins showing on the handles. I don't think I have ever seen one outside of the catalog. Hardwood handles, 440 steel blades, nickel silver bolsters. Does your knife, cowhorse, have pins?
1992 catalog has the 'Camillus Woodcract' series, with the 886, but these are Camillus tang stamped with rivets/pins showing. 'Laminate wood handles' other specs the same as above. I have owned these knives.
Catalog 4 (approx 1994) shows the 886B (note the 'B' suffix) again, with the Camillus tang stamping.
Catalog 5 Still has the woodcraft series in it, again with the Camillus stamping, and still, the 886B is there among the other wood handled beauties.
I haven't really answered your question, only given some clues as to the actual date. Perhaps one of the Camillus guys will note this thread and give a real answer.