The Colt Guns were M1895 Potato Diggers, made in 7,62 Russian; (Used by the Czech Legion, as well as regular Tsarist Troops)…also called the M1914 or 15 (Italy also had them in 6,5 Italian for the Naval Coastal Artillery as AA Guns)
The Lewis Guns were 7,62 Russian, Made by BSA ( The Soviets never openly acknowledged their presence even in WW II, although there exist Photos of Siberian Troops marching in the October Revolution Parade in the snow (Nov 41) all armed with Lewis Guns. Where they all went to is anyone’s guess.
As to the Vickers Guns, Ask Dolf Goldsmith, the Vickers and Maxim Guru…I don’t think they appear in either of his Books.
Most of the 7,62 ammo was made by Western Cartridge Co, East Alton, Illinois ( Frost, “The Manufacture of Ammunition”, NRA Publications…Frost did his “apprenticeship”( 1930s) under an exiled Russian Inspector of Ammunition who was at Western in 1916-1918, and remained there after the revolution. That Inspector rose to be Western’s Chief technical whiz on Military ammo in the 20s and 30s, and introduced the Idea of Pre-load annealing to all military (and commercial) ammo, to prevent neck-age cracking, and leaving the “flame marks” on the case necks to prove this (as required by Russian Specs.).)
The USG had billions of .30/06 at war’s end( 1918) which did not have this final anneal, and they all “cracked-up” during the 20s and 30s, so much so that the ammo was withdrawn and used by the National Guard and DCM for Practice only.
Other WWI “Angliski Zakaz” ( “English Contract”) arms include M1911 Pistols , cal .45ACP and ammunition, which are also a little known Russian usage.
The Russians also ordered millions of Component sets for 10,4 Vetterli (Italian) Ammo, as they were in receipt of several hundreds of thousands of Vetterli rifles from Italy; where the ammo was assembled after the components came from the US (it is thought Remington or one of its subsidiaries made the 10,4 components), whether in the UK, Italy or Ruissia, is unclear…certainly the Italians also partook of this Components contract for their own Vetterlies still in service in 10,4mm.