With thanks to David Hamer providing two real Enigma keys,
replication can be made with precision.
Drawings are finalized in AutoCad in preparation for the book.

Master 'M' key:

Replica 'A' Key:
Real key disassembled:
The replica key completed:

The two keys used, were provided by David Hamer from a collection of parts.
Detail of the lower half of the replica key showing the switch actuation projection.