Try contacting a local Historical Society. Maybe searching out magazines that 'cater' to 'old houses', like This Old House magazine. There might be Ads in there to get you started or point you in a direction, of sorts. I know there are 'recycling salvage yards' out there but I can't help you specifically.
This will take some time to research, I'm sure. You may want to consider postponing your renovation until you get your casement. If you're just starting to look for casement (with only a few days to go), there may be some other 'renovator-stoppers' along the way. Don't misunderstand me, please. Maybe you need to take a breather and get your thoughts together about what you want to do AND what material you will need. (3 days is not much leeway, that's all I'm saying.)
My best to ya and hope this helps.
PS: After this afternoon, I won't be back until Tuesday morning but others will be 'around' ...