Floor shifter or not?

I have a B&M Quick Silver ratchet shifter in my '39 Ford and like it.

I was thinking of getting another one for my '71 Dart, making my own upper handle with Mopar shape from flat plate, welding it on and adapting Mopar after market pistol grips.

Problem is, I've never paid close attention to how the grips mount and I'm too cheap to buy a set just to see how to see how they would fit.

I've got bigger things to worry about before messing with this anyway so it's not a current concern but anyone see this working OK?