I was told a long time ago by a gunsmith in the trade, that that particular action style originated from Lincoln Jeffries in Birmingham. Whether they made them in Birmingham, or brought them in from the Continent and finished them up in Britain is open to conjecture. According to the Internet Gun Club, Lincoln Jeffries brought air rifles in from Germany for sale in the UK, so they may have brought-in actions or finished guns as well. I have only ever seen one Lincoln Jeffries gun myself, a box-lock game-gun of 16 or 20-bore, and it did possess those distinctive bolsters on the action. Of course, other Birmingham 'makers' may have made a trip or two to the Continent as well in the dead of night....!

Both Nigel Brown and Douglas Tate are pretty tight-lipped about the firm. Here's some of what the Internet Gun Club has to say about Lincoln Jeffries:

"Son of George Jeffries of Norwich, he was born in Norwich in 1847 and christened George Lincoln Jeffries.
His firm was established prior to 1870, probably in 1868, at 31 Whittall Street, Birmingham.

In 1870 at a London exhibition the firm won a gold medal for workmanship, and in 1879 they won the "Field" 20 guinea prize for choke bores. In 1883, the firm's double express rifles were placed second at the "Field" Rifle Trials.

The firm moved in 1888 to 48 Whittall Street, and in 1889 in Melbourne they were awarded First Order of Merit and a medal.

At some time around 1880-1890 Lincoln Jeffries' son, Lincoln Parkes Jeffries, opened his own business at 28 Whittall Street trading as Lincoln Jeffries Jnr. It seems the business did not trade for long, he probably re-joined his father, and eventually he took over the firm.

In about 1895, many gunmakers were trying to increase the power of their guns and decrease the weight (resulting in the obvious problem of an increase in recoil), but Lincoln Jeffries gained a positive reputation for their lightweight shotguns indeed, they later claimed to have been the originators and inventors of lightweight 12 bore breechloaders and used "Light Weight" as their registered trade mark."