Flathead(8BA) Automatic Transmission Options/Question

[flatrod]

Looking at your picture of your C4, I see it has a floor shifted lever, which is Mustang, but the neutral safety switch has been removed and a shifter arm bolted on, to make it something other.
If you want column shift, I would replace that arm with a factory column shift arm and go back with the stock neutral safety switch. You really do need and want a neutral switch. Also don't forget the kick down linkage. You have the Mustang cable part now but may want to change that to a column shift arm too. Lokar probably has a cable kit for that, so look there.