Have you checked Ebay.... I found a couple on there...here are the links:
http://crafts.search.ebay.com/1930s-reproduction-fabrics_Crafts_W0QQfkrZ1QQfromZR8QQsacatZ14339QQsa titleZ1930Q27sQ20reproductionQ20fabricsQQsubmitsea rchZSearch
eBay - 1930's reproduction fabrics, 1930's reproduction fabrics Crafts, Fabric, Embroidery items on eBay.com
http://search.ebay.com/search/search.dll?sofocus=bs&sbrftog=1&from=R10&submitsearch=Search&satitle=feedsacks&sacat=14339%26catref%3DC6&sargn=-1%26saslc%3D2&sadis=200&fpos=54893&ftrt=1&ftrv=1&saprclo=&saprchi=&fsop=1%26fsoo%3D1&coaction=compare&copagenum=1&coentrypage=search
eBay - feedsacks, feedsacks Crafts, Fabric, Quilting items on eBay.com