1966 Mustang Drivers Seat Material

[Mustang Silly]

Hi, the inner panel on the base of the drivers seat on my Mustang has frayed yet all the remainder of the interior is excellent (including the remainder of the drivers seat). An Upholsterer can sew in a replacement patch if I could locate the material but I cant trace a Manufacturer who will supply. Is anyone on PH breaking a 1966 Mustang with Turquoise interior?
The alternative is to buy a replacement cover kit which would be quite expensive considering the remaining upholstery is very good.

Any suggestions?