You have several options--Buffalo Arms lists .35 Winchester self loader ammo
http://www.buffaloarms.com/browse.cfm/4,4124.html
Old Western Scrounger
http://www.ows-ammo.com/catalog/prod...roducts_id/450
Gad's Custom Cartridge
http://www.gadcustomcartridges.com/
Obsolete Ammo (Bob Shell)
http://www.aco4u.com/ammo/index.html
Good Luck--I have a 1907 WSL in .351 and am looking forward to shooting it