Donald Dallas’ book “Alexander Henry Rifle Maker” describes Henry and his employee Daniel Fraser taking out Patent number 1559 on 21st April 1877 for the unorthodox stock to be used in the back position popularised by Farquarson in the 1860s. He states “ The Henry two position rifle is very rare with only twenty four such pieces being recorded in the dimensions book. It will be encountered in both muzzle and breech loading form “
“It seems likely that the unorthodox style of rifle was not permitted in British competitions as most examples were sold abroad to South Africa,India and Australia”
A South African agent Albert P Walshe of Kimberley bought 16 of the two position rifles built.
The original patent is illustrated with a straight hand stock and no cutaway under the comb to accommodate the shoulder but rifle number 5298 built for Albert P Walshe is built as per the illustrations posted earlier and as it appears in Alexander Henry’s for the two position rifle in 1878.
It’s price in 1878 was £30 with sights complete
I seem to remember that there were only 2 or 3 examples known today. I may be misremembering however. In any event, it was a cool rifle to handle. I don't know of any rule that would prevent it from being used historically in Creedmoor shooting, and it would be allowed today. The rifle I examined, however, was not shot at the match. Just brought for show and tell along with 40+ other vintage long-range muzzleloaders (mostly Henrys and Rigbys).
For those that are interested, the Creedmoor 150 is an annual match that is leading up to the 150th anniversary match of the original international match that was held on Creed's Moor, Long Island in 1874. We shoot prone unsupported and many of us are converting to the prone back position so these types of rifles are interesting. Cartridge guns are allowed, but only Remington Rollers and Sharps '74s as they were the only cartridge guns at the original match.