Looks like and American Eagle 405 Sprite engine with the gearbox chopped off.
What's the story behind it Alison?
Its comes from another old Trial & Enduro fellow ,who's son has it in his shed.
The son worked with Steven and is also a dedicated T&E member,this being the same club that Tossa's dad is/was involved in.
I'll speak with Tossa more, it will probably tie in with post #343 on this Sprite thread.
......and no you cant buy it,cause he won't hand it over to me
cheers