Thanks very much for the detailed response. These are two bikes i am going to view among others,
http://www.ebay.co.uk/itm/Honda-NSR250R-SP-1993-in-Rothmans-colours-with-JHA-exhausts-/171893658879?hash=item2805a914ff:g:A2gAAOSwDNdVzhEm
http://www.ebay.co.uk/itm/HONDA-NSR-250-PGM-SMART-CARD-MODEL-MC28-/181810488544?hash=item2a54bfe4e0:g:VJkAAOSwyQtVr3iR
Any advice?