This is what I use.I go to SAKWiki http://www.sakwiki.com/tiki-index.php , select website list, and then I select the "Swiss Army Collector" site listed under Information Sites. Then I click on Victorinox, and then onto the second page. It shows an approximate date with the various markings Victorinox lists.However, here it is directly.http://e-webtechnologies.com/sak/Victorinox_Stampings___Trademarks_-_Update_12FEB08.pdfThat other site is very useful and has plenty of other good information.
Here is one more homepage with good information:http://www.123hjemmeside.no/Victorinox/25311898It`s the page of our own North Man. As you can see, the term "Elinox" was used from 1957 until 1978 (alox knives until 1974).Your kind of stamp was used between 1973 and 1975. It`s a later version of the Elinox stamp.