In the past there have been a number of posts looking for information on VDM props.
Classic Aircraft Blueprints, Drawings & Manuals | AirCorps Library have just added two VDM manuals (in German) and an
Aeroplane magazine cutaway (VDM Propeller Info Sheet, 12-Apr-1939).
The manuals are
- VDM Propellers Sorted by Model
- Installation of the VDM Propeller
The latter is a good clean copy with lots of photos which are not cropped like my screenshot below.
You may find them elsewhere cheaper or maybe not.