Thanks Mark. I have not found entire spindles, but I did find the bearings and the other parts I needed. Here's a list of part numbers for anyone else looking:
The belt for the deck is K5559-36710
Front Tires are 11x4.00-5 R/W Rib 4 Ply Tire
Deck anti-scalp wheels are K5371-42110
Bearing for the anti-scalp wheels is K5617-72660
The nut and bolt are, respectively, 02574-50100 and 01133-51090
Blades are K5559-34330
The cutting height adjustment knob is called a "dial cam" and it's part number K3011-44430. These fly off during transport sometimes.
The spindle bearing (two per spindle) is part number K5579-34520
That's all I needed but hopefully this list helps other people too.