Good news, thought for the price i'd risk the PowerBook 100 AC adapter and it works a charm.

Very interesting using one of the earlyer PowerBooks for the first time. The LCDs contrast seems to wash out sometimes but a tiny adjustment fixes it and seems to get more stable the longer it's used. I wonder how easy it would be to open up the old Ni-Cd battery pack and replace it with Li-On cells as its just a simple positive and negative connector. Either way the main thing for now is she works great.