vintage Germany cartography tool, inches to miles map counter gauge w/ compass

Old German made mapmaker or map collectors tool - an inches to miles counter gauge, with directional compass on the reverse side.

This measures 1 1/4" across the glass dome covered dials, and is not marked with a maker's name at all, the leather case is marked only Made in Germany.

The nickel plated housing looks very good, without rust. The counter appears to work fine, though the compass is 'stuck', not moving at all.