they were used to secure / mount the chassis on the assembly line
I have a couple of pic's in the slider-gallery on my site @ 914werke.com
If you can lift all point simultaneously like with a Quick Jack or similar they can work
but if you are lifting on one or the other donut exclusively DONT, they will allow underlying rot
in under the triangles to bend at the rear, or can divot the floor pan in the front.