Just bought my first one, looking forward to camping in her and getting to understand how things work, and where to find stuff!
First thing I want to find out about is the leisure battery. Are they housed in the same spot on each bongo? If so, where? If not, what locations should I look for it, please?
I think you might be better off posting on one of the Bongo owners websites. They seem like a friendly group and will be able to answer your questions I would think.
Try http://www.igmaynard.co.uk/bongo/forum/index.php?mobile=desktop for any help you need.
The leisure battery could be anywhere on a Bongo, but usually on the near side under the bonnet. However, if you already have a battery there, it may well be that you have a Bongo from Northern Japan where they fitted a second starter battery.