RE: Ben Pearson Cougar...??
I don't remember the length on the Cougar--think it's 60" or 62"? You can find out my measuring. Get a cloth tape and start at the top of the string groove. Measure along the side, following the contour on the limb, through the center of the riser, to the top of the other string loop. That will be the AMO length of the bow.
For the string, it should get a string about 4" shorter than the AMO bow length. Dacron only, endless or flemish.
The draw weight and AMO length should be in ink on the side of the riser. Some also had the draw weight marked under the strike plate.
Nice old bow.
Chad