Pretty sure I have a couple regulaters here for a one wire and thats all you have to change to make it a one wire.. but I am going in for a new knee next week so if your not in a hurry I will find them when I can walk again in about 3 weeks or so.. but you should  be able to order one online easy just swap out the regulater for a selfexciting regulater and your good to go.. they are super easy to convert .. I seem to remember that just runing a wire form the bat terminal to one side of a regular regulater plug works to but I would have look back on some papers or notees..I think if you went to any starter alternater in your area they would or could get you a one wire alt.. if your still looking when I get my dismemberd leg working I am sure I have a couple here some place.. do a little google and I am sure you can find a wiring schematic of some pictures with everything you need to know.. ..