We have copies of these maps folded in Ordnance Survey covers, in good condition. Further details will hopefully appear soon, but in the meantime please contact us with your requirements.
Full details of this series, and over 1,000 other map series, including all the variant editions, and any related district maps can be found in Ordnance Survey small-scale maps : indexes 1801-1998 by Roger Hellyer. Far more than just index diagrams.
You might also be interested in Map cover art by John Paddy Browne, which is the standard work on Ordnance Survey map covers.