Featured Antique Chair-Age?Should I reseat it?

Agreed. Like I said above, I think it's original to the chair. And even if it isn't, it represents a meaningful investment of time and work on somebody's part, long ago. Why not keep it?

 

The needlepoint is quite nice and if you have ever done any needlepoint, even that with the floral center part already done, you know how times consuming needlepoint can be. My mother did needlepoint for the seats of 7 old farm pressed back chairs from the farm in Indiana and it took her a couple of years to finish them, but when installed on the chairs they were exquisite--far prettier than the pressed cardboard, leather, or cane seats that one normally finds in those chairs and more comfortable, too.
Respect the time the person who did the needlepoint, have it cleaned, and reuse it even if you do not reuse it on this chair.
Barbara