Hello Colin, the Champion de Crespigny family appear in BLG 1969 (sadly I don't own this volume and am attempting to wrangle Google Books into showing what I want to see...); the head is Charles Leonard Champion de Crespigny, 'of Westbury-on-Trym, Glos., s. his kinsman Sir Vivian Tyrell Champion de Crespigny, 8th and last Bt as senior representative of the family 1952'.
A little online searching shows Charles Leonard Champion de Crespigny (1898-1977) to be s. of Charles Stanley C. de C. (1848-) and Emily Haddon. Charles Stanley C. de C. was son of Charles John C. de C. (1814-1880) and Emma Margaret Smith; Charles John C. de C. was eldest s. of Charles Fox C. de C. (1785-) and Eliza Julia, dau. of John Trent, of Dillington House, Somerset.
Charles Fox C. de C. was fourth son of Philip C. de C. (-1803), King's Proctor, M.P. for Aldeburgh, Suffolk. It was Philip's elder brother, Claude, that was created Baronet in 1805. Both were sons of Philip Champion de Crespigny, of Champion Lodge, Camberwell, Proctor of the Courts of Admiralty and Arches. For further ancestry BP 1878 p. 334 can be viewed here:
https://books.google.co.uk/books?id=YyJNAQAAMAAJ&q=Champion#v=snippet&q=Champion&f=false