There was a question mark in there.
But its a lot of work for a home made job, unless they were a panel beater or a tinsmith etc
My brother had a gas speedboat a while ago and he needed a fuel tank, you know, shaped to fit around all the bits and bobs, and he was working at Hawker Siddely in Kingston at the time (just shows how long ago it was).
We did a sketch and he gave this to an aircraft grade sheet matal man in the workshop, and he made an absolutely spiffing tank, beautiful, a work of art AND pressure tested to boot, welded in Harrier grade alloy naturally. Took him a couple of lunchtimes.
When you know what to do of course these things are easy
Ashley