You have about summed up the distribution, based on what has appeared in books on Colt over the years.

The M-1909 is just a military variant of the New Service model, as is the later M-1917 in .45 ACP.

However, the '09 was made for a special .45 Colt round, with a wider rim, to insure reliable extraction. It was loaded only by Frankford Arsenal, I believe, and none of the ammo was ever sold commercially, except later maybe, as surplus.

The M-1909 was a stop-gap to get a .45 in the hands of troops mainly in the Phillipines, until a .45 automatic could be adopted. After the M-1911 was adopted, it was gradually phased out of service. It was conventionally blued, not Parkerized.

Presumably, you are aware of the exceptional need for a powerful handgun during the Moro Wars.

T-Star