Right now on ebay, there is a buy it now for 55.00. A bobbin hook and base assembly with screws. Is this what you need? or just that screw? There are also vintage bobbin cases in case you can't find the bobbin case pull. Again, shoot an email to Glenn and I'm bettin he can help you.
http://www.ebay.com/itm/Original-194...item3a88509c70