Potentially catastrophic fork failure!
Fortunately this occurred while the Rad was in the shop for maintenance - replacing the front wheel. Had this happened on the road the consequences could have been very serious.
As you can see from the photos, one of the fork blades snapped in half completely when only subjected to light pressure by one of the mechanics. The structure was compromised by internal rusting.
There is also external scarring on the remaining fork blade - indicating that a crack can be present there also! Please check your WR's for similar defects!
I would add that this fork is from a post 1970 Waffenrad - when the build quality was decreasing. It can be that older bikes (paradoxically) may have better endurance. Having said this, you should get your forks (and frame) checked by a good mechanic if you can!
Comments
Some more photos!
Pretty intense!
The rust-problem we have to start working against by having yearly checks,
and most probably start introducing the anti-oxidation baths regarding full frames!
we can offer our members a frame check by our experts - David and also Andras who is a professional frame builder.
I now have a replacement fork for the 71 Rad. Sourced this from willhaben.at (User name: Witti). They seem to have a good selection of Waffenrad parts.

Thanks for the detailed description and analysis!