Reupholstery Help?

I was doing a search for reupholstery information and found several threads on “the straightdope,” but none that answered my particular question, so I decided to join and start posting myself.

Anywhooooo. . . . I got an old Morris chair from the large item pick-up. The guy who gave it to me said that it was his mother’s and he thought it was over a hundred years old, although my research indicates that it is probably from about 1929. The chair was in horrid condition after sitting for years in an outbuilding, but I cleaned it and refinished it (the original finish had long ago been stripped). I was about to find a stain that was very close to what was originally used. I began taking off the old upholstery and discovered that it had been reupholstered before. the original (I assume leather) had been replaced with an oilcloth type fabric (something like what I would call pleather today). The real question that I have though is what to replace the stuffing with.

Under the bottom burlap layer of fabric there is straw (perhaps sea grass) and then horse hair. I want the chair to look as much like it originally did as possible. What should I use to replace the original batting? And where do I get it?

I had the same problem with this stool I’m working on - I ended up keeping the horsehair, because I couldn’t find a source (barring an actual horse - I did have access, but it seemed kinf of extreme) and it was in good shape.