Gas Tank Replacement for 1978 E29

I just removed the old leaking gas tank in my 1978 E29, berthed in San Francisco. Any information on replacement tanks from people who have been down the same path would be greatly appreciated.

Thank You
Bob

Is your tank aluminum or steel? I want to have my aluminum tank vatted to clean it out.

When I swapped out the Atomic-4 with a diesel about ten years ago, I made a tank that fit in the keel. (weight mid-ship, weight lower, good - yes?). This is definitely not a "off the self" idea, but it always helps to have ideas.

Hopefully, the attachmented photos will come through.