Yorkt0wn

I am a new member and have joined this forum hoping to get some advice and guidance. My 15 year old son is interested in doing restoration work on motor cycles and cars. He has recently been given a Yamaha Chappy model LB80II-A which needs quite a bit of working to get going. We have searched around on the internet to see what we can find out about these motor cycles but don't seem to find much information. I am concerned that he will need to spend money to get it back into working order and am keen for him not to waste money that he may not get back. Are these motorbikes worth anything? Can anybody suggest how I might find out more information about them?