My Father-in-law's head lamp had a part that broak so we whipped up a replacement. See the pictures. The lamp was bought from Amazon at:
http://www.amazon.com/STREAMLED-Zoomable-Headlamp-Headlight-Battery/dp/B009P6H738/ref=sr_1_1?ie=UTF8&qid=1420573580&sr=8-1&keywords=CREE+XML+T6+1200+Lumens+LED+Zoomable+HeadLight#productDetails

Perhaps this will help someone else...