I bought both the Klunk bushings (one that mounts in trunk, and the long one you show) from mbclassics.de
I went for the aftermarket ones after chatting with Alexander (vendor).
I have installed the trunk mount and it made a nice difference. Have not installed the long one as it looks way more involved and will do it at some later date.
If you are shipping to USA , you won’t pay the 19% tax but will pay a little extra for shipping. Great vendor. Have bought a bunch of parts from him.