Here's the kit.
http://www.bernzomatic.com/PRODUCTS/KITS/TORCHKITS/tabid/215/ctl/Detail/mid/1147/xmid/6954/xmfid/3/Default.aspx
Here's the contact info.
BernzOmatic Customer Service
200 Old Wilson Bridge Road
Columbus, OH USA 43085-0391
866-WC-TANKS (866-928-2657)
Email or call them. Tell them you need a replacement regulator for the O2. Should be right around 12 bucks for the replacement.