All I can add that may pertain to that gun is this:
Brit Contract version 3.A. “.455 Mark II HE - 2nd Model” (sans extractor barrel shroud and 3rd lock), but with slightly larger cylinder/frame window dimensions from versions 1. the ".44 HE 1st Model Triple Lock" factory converted to .455, and 2. the ".455 HE 1st Model TL" produced in .455.
The 2nd Model continued in the .455 1st Model TL Brit serial range beginning #5462 to #74755, shipped 1915-17.
By Feb 1916 724* were manufactured for the Canadians, chambered in 45 Colt, presumed for the RCMP [H of S&W, pg. 203].
Another 15** in 45 Colt were sold commercially in 1916.
The Canadian military also bought 14,500 .455 2nd Models [H of S&W, pg. 203].
And 1105 2nd Models were released for commercial sales in the US, shipped Dec 1917 to Shapleigh Hardware in St. Louis [S&W, N&J pg. 216].
*””Roy's comments on that model might be helpful here [regarding an original Factory .45 Colt # 747xx that shipped on May 4, 1917]: "Between April and June 1917 Smith & Wesson manufactured 700 units of 2nd Models that are listed in the manufacturing records as .45 Colt caliber. Unfortunately the manufacturing records did not record serial numbers. The shipping records for this model list, in this same time period, the sale of 703 units, but the shipping records do not list the caliber. I am positive that the sale of these 703 units are the .45 Colt listed in the manufacturing records. The extra 3 units could have been manufactured from revolvers that had already been assembled. ”Roy Jinks” Bob (Bettis1)
“The 727 [724]number could be correct but there have only been a small number that are from this shipment, less than 20 documented.” Jim Fisher ‘bmg60’
2nd Model Hand Ejector - 45 LC?
**“The run of 15 with consecutive serial numbers, made in 1916 are all commercial, #46748 from that range is documented. There is no cal markings on this gun and the only other markings are the standard. Roy had to research the build records to find them because the shipping records didn’t list the Cal. The front sights on these factory chambered for.45 Colt is a little higher [than 455 revolvers]. This is the only one of the 15 that is known. Roy said he guessed the other 14 were for a shipment to some other country.” Jim Fisher ‘bmg60’
2nd Model Hand Ejector - 45 LC?