Henry C. Squires was a catalog company, selling directly to individuals out of No. 1 Courtlandt Street, New York City. I clearly see information on the web indicating they printed retail catalogs and offered mail orders and most likely had a storefront on Courtlandt Street. I can find no information that leads me to believe they were a direct distributor for Smith & Wesson. They could have bought inventory uptown from M. W. Robinson at wholesale prices for resale. The early distributors were J. W. Storrs who was S&Ws sole early distributor until the late 1860s when M. W. Robinson, also said to be the sole agent started handling S&Ws when Storr ended their dealership in 1869 by some reports. If M. W. Robinson was ever a sole distributor, it could not have lasted very long. Many guns went to England and Europe and I believe they did not use Robinson for shipping.
Having said that, I can find no information indicating when S&W started selling wholesale to other distributors before around 1871. We know that companies like Beakeart in San Francisco and Shapley in St. Louis were ordering direct from S&W by the late 1800s, If you look on page 38 of John Parsons book, you will find that Robinson took over the New York agency in 1869 from Storr who was Robinson's former employee.
A business card from around 1870 clearly shows that MW Robinson claimed to be the sole agent for S&W. By May, 1871, any proprietary claims made by Robinson was null and void since there were at least 14 companies receiving a letter about ordering pistols in quantities less than 100. it appears that they would be charged more than if they bought more than 100 units per order. This letter went out to 14 agents plus Colonel Schofield, page 178-179 of Parson's book.
The guns are chrome, not nickel as noted above. The difference is not too hard to discern, with nickel being a soft luster, often with a slight yellow undertone and chrome looks like a car bumper, deep mirror shine in appearance. Unfortunately, chrome is much harder to strip than nickel. My guess is that both the above chromed guns were done some time after the turn of the Twentieth Century. You will also notice that the hammer, top latch, trigger, and trigger guard was plated instead of original factory blue or case colored.