In post #43, last pic is the new brace for the fan. It has already sheared the bolt holding it to the block. Time for a new fan blade. This one has one broken blade which throws it way out of balance. Toro wants $95 for one, but I found a better price, $71.
This is supposed to be braced from both sides of the block (red arrow, alternator tensioner).
I am tempted to just go with an electric fan, but the rear support it welded into the motor mount. I can cut it loose from that. Kind of a 'catch 22'.
Here is another spare part I forgot about. 90 degree box for the mower deck: