Just picked up a Metz 403 Flash unit in mint condition - it must have sat in a box for a decade or two. Its minus the battery. I have a couple of old junk 402's in the basement and the battery needed is clearly different. I was toying with using the 403 as a back up unit working events and have since crawled every inch of the web (Metz is no help) looking for a hint as to what the newer replacment battery that would fit it is. Any of you old timers have a 403, or have an idea about the battery? I saw one posting where a "510 zinc #497" battery is noted as working, but I can't find a trace of that one either or the terminology the psoter used is wrong. Help!!!!!?