Three fold sheets (p.: maps(chiefly col.) in pocket.
Chairman: Sir David Serpell.
OBNB doesn't sell books, but you may be able to find a copy at one of these websites:
Report of the Ordnance Survey Review Committee. Published by H.M.S.O. in 1979. Publication and catalogue information, links to buy online and reader comments.
obnb.uk is a Good Stuff website.