Hey guys. Maybe I am overlooking the obvious, but what does the SRD Mark I see often on hones (Droescher I assume) have to do with Swaty Hones?

Also, a possibly related question, I have several Franz Swaty hones, some with 2 lines of text, and some with 3. Yet I just saw an Ebay sale that has an SRD Swaty that has text that says 'Swaty three line Razor Hone' on the stone. What is the story?

http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA:IT&ih=012