Ford 4500

An old friend died. His grandson bought his Ford 4500 backhoe. The swing tower has been neglected way too long. The bottom bushing wore out forever ago. It wore until pressure caused cracks in the metal where the bottom bushing should be. It landed in my lap today. Can anyone tell me what this metal is. It appears to be cast, but has factory looking welds on it.
Options as I see them are to weld to build it up, then line bore, or cut it off, and weld on freshly machined steel in its place....

Ford 4500

Ford 4500