Solo Seat Backrest Mounting

I know ths topic has been beaten into submission, but is don't seem to be able to find an answer to my question. I have a Mustang riders seat, don't use the passenger seat. I want a riders backrest, but the PO didn't order the backrest compatible seat from Mustang. I like the west and font want to replace it, but really want a backrest. Does anyone make a backrest that will maybe bolt to the two bold under the seat for the passenger seat! I see Ultimate had one intended for the King seat, but I am not sure it will work with the mustang and it cost about as much as a new seat by itself. I would rather not cut or modify my seat if avoidable. I find it hard to believe ther are no options for aftermarket back rests with a solo aftermarket seat. The utopia backrest looks perfect, but only works with stick seats it says.