Bring it to you local technical college metal shop. This looks like a good project for them. They might be able to test it to see if it is indeed cracked.
If it is, they can weld it and clean it up. Looks like a good project for an advanced metals shop class.
If it is cracked and you decide to have it welded, be sure to drill a hole at the very top of the crack before doing the welding repair work.