Lost this thread (thought it was in 66/67 Tech)
and I was going to take a pic but my batteries are dead, go figure.
Pics to follow.
In the meantime if you look at the two studs that are right by the hole you'll have a good reference point. Using the center of the stud (I'm looking at the underside) the rearmost portion of the hole is 5/8ths of an inch away. LH side of the existing hole is an excellent reference point, as I can still see evidence of it's existence on 2 factory consoles. So that side simply gets extended for a front-to-rear total of 7 7/16". The hole is wider too, but it all comes off of the RH side with the width being 3 3/8".
These measurements are just for the metal top, it only now occured to me that there might be different opening size for the plastic bottom (don't think so, but it never hurts to check?) so I'll definitely revisit this topic.