Welcome to AA.
, the best advice is to have a pro fix the tank. I admire your courage, but with a broken center brace and bowed glass, it's likely specialized clamps and other tools will be needed.
I'd contact local glass companies, or mom and pop aquarium shops for estimates. A 240 gal
. Is a fantasy tank for most of us, don't let it become a nightmare.
My work buddy's resealed 180 gal
. Failed, flooding his house with salt water. Several thousand
dollar loss in fish and coral. Not good.
Good luck with your project.