I need a new one and I don't know who manufactures the old seal. Will most seals, as long as they're close to the right size, work? It's about an inch wide and made of a woven material

I have a fair bit of experience with replacing them having heated my homes with a woodstoves my whole adult life. Make sure you know the correct diameter. If it requires a 5/8" and you use a 1/2" you probably won't get a proper seal. The generic mass produced ones sold here at most hardware type stores have a poor quality adhesive that only lasts a couple seasons before it disintegrates and your gasket begins to fall away. (yes, I installed them correctly). If you have a decent quality stove you should be able to order on line from the manufacture an actual replacement gasket for that unit and the material and adhesive will be of a superior quality. That's been my experience.

measure the gasket groove and google stove gaskets.
easy to replace.
RR

I called the guy I bought it from and got voicemail, his website says, temporarily closed. I don't see where the manufacturer has a website

Most hardware stores or glass shops should have it in stock.

I’ve done a couple three with the kits from the hardware store with good results. Lasted several years and still going strong. Be sure to read the instructions for the glue. It has to be completely dry before the first fire.