I have a Lokar shifter in my bird. Black lexan is what was used to mount the boot to the console using the existing screw holes for that held the original shifter bezel.
When the hole was cut in the tunnel it was made just big enough to get the linkage thru.
did you relocate the console when you did your shifter install? In the picture it looks as if your console is farther back in relation to your seats? I have a 67 console for my car but went with the universal megashifter. When I installed my shifter where I wanted it was farther back than where the original console would be located. So I have yet to reinstall my console.