No need for a new tank. Just pop those screw heads off. They are soft and should come off with a cold chisel. Drill them out if they do not cooperate. Drill the remainder out of the tank and chase the threads. Who knows, some may come out with a screwdriver. Just remember to clean the tank out well.

As for the pump bracket, just get someone to braze a new elbow on there. You should be good to go.

Good Luck,
Michael