Winchester made knives from around 1920 until WWII, then stopped to focus on their arms for the war effort. In the 1970's some inexpensive knives bearing the Winchester name were produced in Germany, unauthorized by Winchester. Your knife is a German Winchester. If you go to this page
http://www.jaysknives.com/winchester_2.htm you can see some examples of some other German Winchester knives with an identical stamp.
All of the Winchester knives made prior to WWII had a tang stamp that reads as follows:
WINCHESTER
-TRADE MARK-
MADE IN USA
The opposite side of the main blade always had a model number as well.
This was always found on the main blade at minimum, with the secondary blades sometimes marked with Winchester only, using a characteristic font (not nearly as florid as the one pictured). The WINCHESTER is always upper case in all original and officially licensed reproductions I have seen.
In the 1980's Queen acquired the original tooling for the original Winchester knives and began making licensed reproductions, using the original tang stamps (made by the original tooling). In addition to the model number on the main blade, the year of production was also stamped on main blade (this is also found on the Case Classic knives of that era), and in every one of the licensed reproductions I have seen the full tang stamp (WINCHESETER, -TRADE MARK-, MADE IN USA) is used on every blade.
From what I understand, the plant manager at the time was the legendary Bill Howard, who later went on to start GEC. At the same time these knives were being made, so were the Case Classic knives, which were mostly made by Queen as well, with some being made by Case. The Case Classic knives, like the Queen made Winchesters, were of superb quality (some say the finest knives Queen ever made). Since these were made in the same plant at the same time, you can also find some Case Winchester knives on the collector market as well.
We know of the licensed reproductions today as the "Black Box Winchesters" that were sold by Bluegrass Cutlery (
http://www.bladeforums.com/forums/showthread.php/562111-quot-Black-Box-quot-Winchesters). They were made with 1095 steel, very well fit and finished, and have some of the finest jigged bone and stag handles ever seen on any production knives. Here is my personal favorite, which is now my EDC:
This is it when it was brand new (about 2 years ago) - Note the font and tang stamp
Here it is after carrying it and using it like the makers would want it to be used
These knives were made into the 1990's, with the later knives going through some stylistic changes, and apparently there were some other makers involved later on (Camillus, for example). The knives that came later were often issued in white boxes as well as the black boxes, and the quality, while remaining high, is considered to have dropped a bit during the late 1990's. Here is an example of a 1996 Winchester which was rehandled because the celluloid handles gassed out on the knife (beware of any celluloid handle knife...it is always a crapshoot). Although this was a later knife, the fit and finish is outstanding and rock solid. This particular knife is one of the strongest knives I have ever seen:
You can still find the black box Winchesters on eBay and elsewhere, and, mostly because the current Asian made Winchesters are so inexpensive and comparatively very poorly made (causing the brand to erode), they can often be acquired for a very reasonable price compared to a knife of equal quality made by GEC or Queen.