Replace it. Weld 3/4” shaft stubs on the ends of the steel tank. Attach two flange bearings to some channel stock and place the bearings onto the shafts. Fill the tank with sand or water, cap it, and you now have a really nice lawn roller for about $30.00. If you want it to push by hand, bend the channel stock into a Y and attach a T handle. If you have a rider mower, make a hitch hole in the Y and pin it to your riding mower. Your lawn will be as smooth as a tennis court in two months.
>> really nice lawn roller
That idea is a “keeper”. Thanks.
IIRC a young Arnold Schwarzenegger started building up by pushing a dead heater tank in circles!