Pretty steam punk looking. Needs some old vintage brass gages and copper lines to go with it and then maybe turn it into a urinal.I would be leery about using it as a pressure vessel, but it does look cool.
Did he get the merlins out of the bomber?I have that same cylinder. My Dad got it out of a Lancaster bomber he bought in 1946. There were a hundred of so Lancaster bombers parked on Western Canada rural airports. Our farm was near Medicine Hat. This is where Dad got his bomber. He took it apart for the components and hydraulic oil.
The tank is stainless steel. I have seen them used a fishing net buoys.
I am going to try and make the walk to my shop tomorrow. I have 23,000 or more pictures but not one of this tank.
It is my understanding this tank was used for low pressure oxygen for the pilots when they were high altitude flying.