that one was for a 24f as others have confirmed. The group 22 holdown is wider because the battery is shorter then the 24F. Bob
Thanks for the further confirmation Bob, though I had no reason to doubt Charles' post. I realized I had swapped the group numbers (which I'm prone to do), and actually went back to correct my original post but Charles had already posted his reply! He's quick on that keyboard!
I am fully aware that particular (short) hold down is for the larger case, heavy duty, group 24 battery (and conversely the hold down for standard duty, or group 22 battery is the long one). I stated the Ebay hold down referenced by the OP was for the heavy duty battery in my reply.
One reason I specifically used the term "heavy duty", is knowing I frequently swap the group numbers. It's a 50/50 shot to get the group number correct, and half the time I mix them up!
My '66 fastback originally came with the heavy duty battery, which was determined from (fortunately!), locating a copy of the build sheet! Thanks for your comments though.