My lady is very handy with a sewing machine for this sort of project so my thought after Bob's response of lack of used ones is to make one. As long as you have the original pieces as models and if there are any mounting pieces that need to be reused, the shapes look pretty simple. You can get foam and vinyl easily. Even if you can't get it done "in-house" you could probably find a canvas place or automotive upholstery place that could do it, although pricier.Does anyone have a bottom seat pad in good shape they would wanna sell ?
Nice job bringing that one back to life!