graydog fired this
volley in oups.com:

The U shaped pushrod end measures 5/16" OD, (not 1/4" or 3/8")

A "U" shape with a _diameter_... piece of cake!

What you'll need are 5/16" INSIDE DIAMETER staples. They're a little rare,
but I'm sure you'll find them in the "K" drawer, in the #12 staples supply
area of your home-goods store.

Lloyd