Sorry gents. I'm calling BS on both of you. That IS the correct switch for a '61. None of the catalogs carry the earlier switches like this one. So hang on to that one. You can take that to a locksmith-a good old timer, and he'll fix tou right up with a new set of keys for it. It doesn't actually need the key to start the truck. It has a kind of "farmer" set up, where once the switch is in the 2nd position, then you can start and stop the truck at will. If you don't turn it to position 1, (to lock it out) then you will never need a key.
FGT, your link to Jim Carter's locks omits any reference to 60 and 61 trucks at all and proves that even the best of parts companies (I like to think that Carter's is the best) don not carry the 60-61 switch.