Thanks to Kenn Marks for letting me review this student clarinet. I really appreciate the registration card that Kenn sent! See below.
The Duratone is just another Bundy. Bundy went through several different key styles which I have not reviewed. This one has straight attachments (sort of the back-bone for the pad cup) on the left hand joint trill keys. But the keys are definitely those of Bundy. I think it obvious that Olds subcontracted these clarinets from Selmer, marked with their logo, which was applied with a sticker, just like the Bundy logos.