Up for sale here is this set of NOS unused speaker jacks from the 1980s.  These are really nice spring clip speaker terminals!  You get two of them, the same as in the pictures.  I believe these were originally for Koss speakers, but I don't know which ones exactly.  The terminals themselves look identical to the ones on the Koss CM/1010, CM/1020, and CM/1030 speakers, you would just have to remove the terminals from the plate and mount them on your CM speakers.  The mounting holes are each 3.6mm in diameter.  Center-to-center, the holes are 45mm apart.  These are in great condition and will work great for you.  Please see my pictures for details and dimensions. 

US shipping and handling is $6, and international is $20, no matter what quantity you buy. All my small parts are set up for combined shipping, so just use the "add to cart" feature and then check out all at once, and it will combine shipping. If you have any questions, please ask.

I have more terminals and other vintage electronics listed--feel free to take a look!