The chair upholstery was custom woven for the chair in the 18thC. In France. It is known as Aubusson tapestry type of fabric. Very rare. We found a set of 4 chairs for this lucky client! You can still find it with antiques dealers in France. But the chair comes with it-- about 12,0000-20,000 each!
You can find yardage or tapestry fragments that could be worked into a small chair.
Their are also mass produced tapestry fabrics that are available by the yard.
Occasionally I run across mass produced panels that are printed to fit 18th C. Style chairs. These are all ideas you can look into. Good luck with the hunt!

Thank you for all the suggested ideas and the information you have provided. What a find that is! And what a marvelous job with that space! Many many thanks for your time.

You are very welcome. Let me know if I can help in any other way.

You can find Aubusson chairs for less than $12,000, but they are expensive. Look on 1st Dibs, Online Galleries (UK) and Ebay. Estate sales also sometimes have them. Before you buy look at a lot of samples because you will learn the "fakes" from the real thing rather quickly. The old Aubusson chairs have a look and feel to them which cannot be replicated by modern replicas.

You have been incredibly helpful. Many thanks for all the helpful hints, These are useful indicators to help me better understand and have a deeper appreciation for them even if I don't make purchases right away. I sincerely appreciate your feedback. Yes, 1st Dibs has some amazing stuff, and I will look out for estate sales too.. Thank you so much for your valuable suggestions.