Bill at fixmydual is great. That's a nice looking TT there, Fred!
You might want to contact Bill or even vinylnirvana.com. Nirvana has a cabinet guy who makes awesome plinths for this (mainly) Thorens TT's but maybe could fix you up for the Dual.
And Bill can send you a cutout for mounting, you can use it as is in your plinth or as a template for another mounting.
Fred: BTW: those pics looks so awesome I am jealous!
Paul