Howdy John,
Would you do me a favor, and file the depthgauge on a 3/8 chisel cutter that has been filed back to end of life, using that 'Swede' fileguide "file-o-plate" device, and let me know what the depthgauge setting actually measures?
You can measure by setting up with Oregon gaugits or the filemate style tools, until you find the one where the depthgauge is just flush with the guide surface. I would expect the result to be .035 to .040. Could be even lower!
This device has been around for a long time in Sweden, and various depthgauge setting design ends have been tried. This one is a new one to me, and looks like the results might be rather on the hungry side for safety.
Regards,
Walt Galer