I bought a 1905 double ring last week minus the blade holders and cannot find the blade holders anywhere but I found a local 1906 single ring that has what appear to be the same blade holders I am in need of. The 06 single ring blade holders have sharp on one and dull on the other are these also the correct holders for my double ring? Are there any other markings on the other sides or bottom of the blade holders for a double ring? I screwed up the other day and bought another single ring that has silver blade holders thinking they were correct for my double ring another big mistake made on my part.