After several frustrating weeks I've finally managed to fit an original alternator. I've posted another story about the problems I've had.
The picture of your engine bay solved one of the mystery of what intake manifold is on my S2. Apparently my manifold is a copy of the ELSE design. Mine is missing the ELSE logo with no other manufacturing stampings anywhere. Everything else (sorry, couldn't resist) I see in your photo is identical with mine.
While you're at this stage of the restoration, I highly recommend thinking of an effective heat shield to protect the Weber from heat soak along with an air box and a cold air intake. My S2 came with a air box made from two cake pans screwed together with an opening cut out on the bottom, directly above the exhaust header. This along with a relatively small heat shield below the Weber made for a frustrating drive in traffic with a bad stumble getting off the line until the carb cleared out.
I'm currently working on the issue.