Sachs engines move a lot, for not being variated. Here is how I welded up and mounted my gianelli pipe on my 504 1C westlake.
I welded a washer on the front bend, and a brace to close up the snail part.
I put a spring on the front washer and drilled a hole in the fin on the jug. I used a brake return spring to snug it up.
I welded up a bracket that attaches the brace to the engine case.
The pipe fits really tight against the engine case- it actually rings against the transmission. I tried a piece of foam to silence it, but will have to use rubber-like a chunk of radiator hose.
You can also see my super-cheap but not quite free air filter, and the custom square hose clamp holding it on.