Thanks Paul for the links, I have actually seen them before but any information is highly welcomed.
I also own the No.4A mine detector which I intend to make working. Just need to solve the battery problem as these are not available any more according to my information. But I might be wrong. A friend of mine found a B144 EverReady batery in his unit. It is 69V + 1,5V cell, which could work with that but I have to check on it. I found this link for a replica :
http://mysite.wanadoo-members.co.uk/...pages/b114.htm
I might give it a try.
Dusan