Do Disk ][ controller to Duo Disk cables exist?

[basil@rain.org (Basil of Baker St.)]

Now that a few people have confirmed that Disk ][ and Duo Disk (UniDisk)
controller cards are functionally the same, but the Disk ][ has 2 20 pin
connectors and the Duo Disk has a single 19 pin connector, were adapter cables
ever made by Apple or anyone else to run a Duo Disk drive off a Disk ][ card
or vice-versa?

If available, the exact names and part-numbers would be very helpful, as
well as suggestions of mail-order vendors from whom I could buy these?
Perhaps Shreve Systems or Pre-Owned Electronics?

Thank you.
-- 
 Basil Wilson
  basil@rain.org   --   http://www.rain.org/~basil
--