Lambretta small block cylinder kit, it's an ally barrel with cast liner, head is a 175 that's been skimmed for higher compression with a new 66mm piston / rings.
The barrel is a Scooter Restorations 185 64mm that needs boring out to fit the piston as it has a bad score but there's plenty of meat to go out to 66mm & get rid of the scoring.
Will fit any series 1, 2, or 3 & GP 125 or 150 engines without having to change any engine internals.
Was going to use on a project but never got round to it.
I can arrange to get it re-bored if needed at buyers expense, please ask for details.