It's usually the other way round: pre-1917 most Russian makers such as Matska, Maslov and Alyoshkin sourced their guns, at least partly (Kilby barrels) in Britain.
But here is something completely different: a pair of MTs-7 over/unders made in 1979-1980 and sold in Britain as a pair by Arthur Turner Sheffield. Apparently, whoever ran Arthur Turner tried to do the same trick as some modern British firms who sell guns made in Italy and Spain under their own name.
I believe they were not made to order, but bought out of dealer's inventory. TsKIB SOO guns were exported to Great Britain, but they did not sell too well. Their quality was well above their price tag - an obvious business opportunity. Wonder why it didn't catch up.
More on the guns here https://sportingbookworm.wordpress.com/2...-pair-of-mts-7/