I was originally going to mount the lever on the left side of the seat but as I fit the lever on that side I realized that it would interfere with the drivers door.

Because I am making a center console and needed to weld in some mounting brackets for the console I just designed to bracket to be a little longer on one side so that I could drill and tap the bracket and bolt up the E brake lever. For the front mount I used a piece of 1.5" tube notched and welded in at the correct angle with a 1/4" piece of flat stock welded on top to drill and tap.