It looks as though it may have been a twin battery model, or maybe someone has tried to convert it into one. Unfortunately the first piccie shows only one wire to the keyswitch, so it won't work. The second piccie shows the original wiring has also been tampered with so I'd be tempted to replace it. At the risk of sounding like a salesman, the c5alive wiring kit would sort that lot out for you;
http://c5alive.co.uk/ecommerce/product_info.php?cPath=7_21&products_id=195&osCsid=51e42d2530fc5329f7f80e584e918a60..or you could make your own. The download section has all the instructions for the earlier version of this kit. The one we now sell is a better improved version
The beauty of this kit is that it allows fitment of any 12v battery that will fit in the allocated space, bringing you neatly to the ongoing debate of which is best - leisure or car battery
.