OK,
The next step is all you. You have to get EXACT measurements of the space between AND behind both seats. We already know a twelve will not drop into a stock console, so now you have to modify the console so it will fit or make a console from scratch that looks stock. Also you may need the space behind your seats for extra volume. Here is an example from a 58 Chevy:
This one is quite complicated but you can make one similar but less complex.
Mal