The pilot TBird end-user has been great - provided these mock-up pics so we have determined this is where it will go

A 2x4 construction lumber block cut to approx size makes for a great test box
(That is the Key-Switch power connector immediately below the alarm connector - the fuse box has been pulled away to show)
Just final details on which is the best face to exit with the harnesses and their lengths.
The power connector is same series as the R3 later model but is only 6-way but I know I can get it.