To quote Donald Dallas in his book "The Brirish Sporting Gun and Rifle"*,"Out of all the patents[1870's and 1880's]three rose to prominence, two of them still being used to a large extent today. The first of these, an inert lever, the 'grip catch', was very common in the 1870's, but it fell into disuse after this decade, when the more convenient snap fore-end took over. The grip catch was patented by Charles Harvey, an employee with Wilkinson & Son of 27 Pall Mall, London in patent no.1793 of 7 July 1866. A Lefaucheux type forward facing lever turned a screw grip turret in the for-end to engage with a bite on the barrel loop very similar to Henry Jones 1859 underlever. It was handsome, unobtrusive and secure and was used by many makers notably Horsly of York and Rigby of London to the extent it is often termed the 'Rigby lever fore-end'."
As a note I have a pair of 1894 custom made Boss & Co. sxs's
with 'grip catches'. plus 3 H&H rifles that use them for the durability.
*
"The British Sporting Gun and Rifle", Donald Dallas, Quiller Publishing Press. London 2008.
