Broken vacuum advance unit

Good evening,
The vacuum advance unit for my Mercedes SLC 350 -74 is no longer functioning. Tried to open it up to repair, but it's beyond saving sadly. My local Mercedes dealer informed me that the part is no longer made, and I've had no success finding a replacement online. The part number is either A 000 158 1818 or A 000 158 3018, they weren't sure at Mercedes, and neither am I. Anyway, the part number on my distributor is 0 231 403 005. What options do I have? Are there any other vacuum advance units that will work on my car? 000 158 6918 is still available and looks the same. But does it work the same?

Btw, my unit got connections for both advance and retard. But only advance was connected.

Thankful for any information
/Tom

Hi Tom,

that is one of the most difficult parts to find. It is used in 450 and late 350 Europe ignition distributors. Troublesome.

Thank you for replying Volker,

Was afraid of that. Very troublesome indeed. No luck using another unit I suppose?

No