Yeah...pretty much anything for '60-'62 is off the radar!
My theory on why they're always missing is pretty simple: They have to come off to change the water pump. First the shroud is unbolted, then pushed back to the engine block. Oops...you have to remove the fan belt first. Okay, that's done, now you can get your fingers on the fan blade's bolts and remove it, using the radiator as a cheese grater on your knuckles. Fan's off, now you have access to the water pump. Swap out the water pump, get the fan belt back on, install the fan and...oh crap...there's the fan shroud still on the work bench.
Either that, or they just didn't like dealing with the fan shroud and left it off deliberately.
Same process for a radiator repair.
-Brad