I decided to buy a Hoodman Loupe for my DPM cameras and to fix it using a RedRock system.
HoodLoupe 3.0 (PATENT US 7,386,229 B2 and 7,034,877)-Hoodman Corporation
Redrock Micro - microFinder loupe accessory kit
The initial problem was that the RedRock system is designed for DSLR cameras with thicker bodies than the DPM. To attach the connector one needs access to the tripod socket and that was partly hidden.
I took the Redrock connector to a local metal workshop and they extended the hole into a groove.
Now the Loupe can be fitted to the camera.
This is the view from underneath. I have locked the plate on using part of a quick release unit I have had for years. I have no idea what make it is - sorry. But there must be lots of similar small bits of kit around and the advantage is that I can still put my DPM on a tripod.
It works - and it looks much more professional than those bits of rubber that are offered as an alternative.
RedRock have seen what I did. At the moment they have no plans to market a different base unit - but I can assure you that it takes less than a minute to make the alteration if you have the right tools.