As we know there are at least 4 variations of 91mm metal file/saw.
Were there variations on the 111mm knives as well? I'm looking at a used Workchamp but it appears to have a surface similar to the "version 3" 91mm file (case hardened/plated) as opposed to the newer 2005+ stainless.
Wanna be sure get one with the more aggressive file. This ain't the FingenailsChamp.