Most every Ford Flathead parts dealer has gaskets and you should be able to buy an intake manifold gasket as an individual piece. You might even try NAPA.
Thanks Vic. I found one at Mac's. Mac's description starts out as valve cover gasket then goes on to say inlet manifold gasket. My old eyes just missed it.
Wow, my Napa's around here give me a blank look when I want anything for a 1934 or 1937. It can be a pain but thank god for all of the parts guys on the internet.