I don't believe that they've been manufactured in many years. Your only hope is probably that someone is willing to part with one. I did a little searching several years ago, and could never find any kind of manufacturer and part number -- like a Molex or AMP type part number. Finding that might have lead to a unused box of them somewhere...
However, it seems to me that something serviceable could be 3-D printed.
Pin headers work well. We solder them to the 68K so they'll be secure. A plastic framework could be used to press the pin header against the 68K instead -- basically what a Killy Clip is. So, a skilled 3-D print designer might be able to layout something which will snap over the 68K processor and press a pair of header strips against the CPU pins, while allowing the other end of the header strip pins to exit through the top.
If you don't want to do it yourself, you might start a new thread with a snappy title, like "3-D Print New Killy Clips?" or some such. See if you can get one of the printer geniuses interested.