You could ask Rich Cole at http://www.colegun.com. The shape of the part that goes into the bolt is not overly complicated. You might be able to make a complete part from steel, and harden as required, instead of modifying an existing one. After market versions of the operating handle (think that's what it's called) are probably available, too. For example, a Briley handle: http://www.mpcsports.com/index.asp?PageAction=VIEWPROD&ProdID=1859&HS=1 .