I put a chopped pad on my King TP. You will have to drill new holes and you'll have unused holes showing, but it fits.
I have the king tour pack and with the Corbin backrest that's designed for two up......

and I have the king tour pack with the Corbin backrest designed for the solo position.....




I to had to drill holes for the solo position backrest (you can see the two stock holes on either side of the pad in the pics above). I have stainless bolts with cap nuts that I use to plug those holes if I'm going to be riding in the rain. I've seen others use chrome acorn cap nuts or chrome bullet cap nuts.
One guy I talked to told me that he didn't have to drill holes, but I had to, so.............

And for this rider, especially when you're riding 500-800 miles in a day, the most comfortable position of all is in the solo position with the Corbin riders backrest for lower back support and the Corbin solo position backrest pad for upper back support. It's incredable support and the back issues that I used to have when riding long distance are pretty much gone when I ride with it in this position.
I still take my grandkids with me from time to time, so I still have to keep the two up backrest and switch back and forth from time to time.
Hope this helps you figure it out.