Roland: I used Levines IV, but the quality of fit and finish spoke exhibition knife to me, so I would put it to the time period before the markings were sold. I only have a chance to find these kind of knives in person at shows. I have recently had the opportunity to work a table at the Tulsa show with a veteran knife trader with wonderful Sheffield knowledge and he found the knife and I bought it from him as soon as I saw it. Of course I always stand to be corrected, so I hope the UK guys chime in. In any case it is a beautiful knife that I'm proud to own. I have another knife that I will post soon that is also above the norm in fit and finish. Charles