I rebuilt my 48" deck when I inherited the mower with my house. Took it all apart-- take pics to remember how to put it back together. Had a piece of 10 ga steel cut to fit top of deck. Welded it in place used existing holes in remainder to drill or cut out for spindles and idler. Had to fabricate a new spring holder. Rebuilt all spindles and gear box. New anti scalp roller and bracket. Added 1/2" bar to groove all around front of deck where it was getting thin. New coat of paint and a new belt. Had to seal some gaps and crevices with Labmetal filler. Deck still cuts like a new one. You might want to try taking it to a local welding shop to see what it would cost to rebuild top and repair what could be. A couple hundred here might save you several later.