Any ideas on the pre 74 columns?...
Do you have a '73? If so, was it a late-build by any chance? Just wondering if it's late enough, whether you have a turn signal switch that was designed to have a bulb in it already.
The '73's were odd ducks, but if late enough, perhaps it was going to be a running change at Ford?
In a pinch, it's just possible too that a '74 and later turn signal switch could be retrofitted. But it would only work if you also installed a '74-later single-trace horn circuit and notched the column "bell" to accept the hazard flasher switch sticking out of the side.
But hey, even though confidence might be low, some things can still work out!
Paul