That manifold looks exactly like mine on my Alpina equipped engine. Alpina has the serial number of the cars they produced. This could be a very valuable car you have there. Will need a huge restoration, but if it is what it looks like, you are in the money.
I couldn't find an Alpina M30 Weber manifold, but I also noticed that it looked a lot like the Alpina M10 carburator manifolds.
Magnets ussually do not lie...It is a CSL.
Moving forward.
Given the potential provenance of this car, I would reach out to Gerrit, Yanick, or BMWPete via this forum's PM feature and ask for some recommendations on next steps.
Next up! Can you post some pictures of the dashboard and steering wheel? I'm curious to know what wheel it is sporting, and if there are gauges in the speaker holes. You can probably roll the car outside and take a leaf blower to it. That would rid you of the current Indiana Jones look.
To give you a little bit of inspiration about a Colorado Orange Alpina car, here is Yannick's old Inka Orange (more reddish orange) genuine Alpina B2S.
Here is what Colorado looks like: