Wow, just found this ad on a free classifieds site here in Australia.
http://www.gumtree.com.au/s-ad/taroona/laptops/1994-apple-powerbook-150/...
Unfortunately, this place is at the very very very bottom of the island that sits under mainland Australia, and is 100 miles/250km from here.
If you can arrange postage, it would be well worth it.
Cheers.