motorbikes wanted a 50cc or other small brighton

Hello I'm looking for a 50cc bike that i can fix up as transport to beat the traffic. but more importantly, my daugther has experessed an interest in how engines work. so i would like to get something, that i can strip down with her. to show her how engines work. and ultimatly show her how to ride one. anyone have something free or cheep?. I'm on an ebay misson but no joy as yet.