Well, I went for a Yuki 7206. After some modding it didn't turn out too bad. You'll find the story here:
http://rwg.cc/topic/177949-yuki-7206-bracelet-no-longer-accepts-gen-spec-bars#comment-1450950
My mistake, typing error. Apologies for the confusion. To seat the Athaya tube snugly, I used a 6.3 mm x M3-90 degree countersinker first to create the sloping 45 degree angle. Then a ca.3.2 mm drill bit to widen the hole ever so slightly to a depth of ca.0.3 mm. This creates a small step and angled sides for the tube to sit in. I then cleaned, and extended, the remaining case thread carefully using a M3 x 0.35 tap.