CJ7 1981 seat mounting

I bought an 1981 half a year ago. The previous owner installed a new tub and in that process he also installed some non original used seats (not nice at all), but he provided me the original seats.
I've been restoring them and now I need to install them. Unfortunately I cannot find the required bolt pattern. I've tried both Chiltons and Haynes but neither provide me the answer. Off course I could just start drilling but I like to make it as close to original as possible.
So my question. Does anyone have the required drill pattern, the measures or a picture of a cj7 tub with the holes for the front seats?
Thanks
Henrik