With thanks to ~Angel~ and warren, there was an interesting entry from 2007 about these rare wire cutters.

1917 No.1 MKII Wire Cutter for ShtLE Rifle (click here)

This MKLicon entry includes on-line videos demonstrating how the wire cutter works when mounted on an Enfield Rifleicon, as well as feedback from MILSURPS.COM member "warren", who describes its operation in detail.

Regards,
Doug