This is what I know:
I have a Harmonia Bassoon, Made in Paris. It is made of maple, with 4 thumb keys on the tenor joint, and it's really old. It plays great, but I don't know much about it or the company who made it. It is serial number 52.
If anyone knows anything useful about the maker, etc, please post here.
Thanks very much!
I've had a look at the ebay pic and it's a Cabart, as contra448 thought. Cabart are the only bassoon I know of that has a roller on the low B key as standard.Also Cabart had a serrated whisper key touchpiece which is unusual.
Alright, well thanks very much for the information. It does play very well, and I have gotten a lot of enjoyment when I've had the opportunity to play it. I'm honestly a little surprised by how old it probably is, but when I've owned it I've taken very good care of it. I hope the person who buys it on Ebay likes it as much as I have!