I got it sorted. Just needed to use the refil key. I also played about with the percentage as it was set to 98% or something & was giving JP's every 5 minutes and it was nearly always repeating (repeated 3 times last night!). Its on 74% now so it should be a bit more like what I'm used to! I also changed it back to £10 JP & replaced the decal, as the £15 JP decal was just a home made one & looked awful!
I think I might be OK to keep it now, thankfully, as I managed to talk my girlfried round (via bribery!), but I am still curious as to how much they go for generally. I can't find any for sale on the net (apart from Kung Fu Club which is around £250 - £300). So if anyone could advise me I would be most grateful.
Thanks again.