I don't know the name of that bag but just want to comment that the seller has several listings described as "Bonnie Cashin" era that aren't close to BC era and she also sold this fake:Haven't come across this saddle bag before:
http://www.ebay.com/itm/201693893730?_trksid=p2047675.m570.l5999&_trkparms=gh1g=I201693893730.N36.S2.R2.TR15
http://www.ebay.com/itm/Vintage-Coa...D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557