Where can I buy a 1930's salvation army bonnet?

I'm not sure if this is for use at the Salvation Army or for "Guys & Dolls" but here's some idea.

Firstly you could try a Salvation Army charity shop. Failing that you could try Ebay, there's one on Ebay.co.uk at the moment for £10 or one on Ebay.com for $15. Or you can place a want ad in the local paper, or so on.