Lordy, I found I could solve my problem
And I remember the old tree stand manufacturer warmly.
I had cloth covers, with zippers, where I could replace the worn foam cushion. I fondly remember the kind clerk at the woman's fabric center who cut me new foam to size. It made my old tree stand all new again.
I guess a man, the hunter, would be out of luck without zippers on those foam seats. Personally, I never got taught well to be a tailor.