Great description. I know much more now. NOT
Theres plenty of those superchargers about. IIRC BMW changed them as a recall and gave the original back to the owners.
There will be loads of chavs fitting them to there mums mini's.
Went for 103 quid - as this had the head it was probably the John Cooper conversion. If BMW did a recall they would not give the s/c's back to the owners, they would gbo back to the supplier under their warranty system. IIRC this engine is the Brazilian Chevrolet lump - which will be phased out when -the new Mini launches next September ('06)
Sorry if it confused - when the cooper conversion is done they swap the head and the s/c for a higher capacity unit.
£103 is a very cheap way to turn a Cooper into an S, I should think it is the bits left after a John Cooper conversion, or similar.