It is an interesting kit, but no evidence of any especially unique "early" parts, although maybe the comment is meant to reflect that the parts are VSM, but no pics are shown of any VSM markings.
The jacket appears to be Colt due to the placement of the rear water plug hole, which is the same as Colt, and the crisp and clean edge of the trunnion and jacket joint, which is typical of Colt. Some Vickers guns have a very similar clean step at the joint, but usually not as clean as the Colt. Many of the WWI guns have the step blended. In my opinion the jacket is not Colt, but VSM. Front sight is Brit not US and as noted there is no Colt ID where it is usually found on Colt front end caps.
Grip is clearly Colt with the wide arms, compared to VSM that are narrow. That could have been added add any time in the travels and history of the gun since G.B. hax a lot of US 1915s, etc.
There is no mention in the story as to why Colt would have supplied the guns and tripods.....did I miss that? Colt tripods is the most mysterious part of this offering, IMO.
Although detail is missing in the pics, no other parts appear to have the usual Colt u\v stamp on them. In my view, the parts are Brit, which seems to be more logical than to be US. If the parts were Colt, the value would be much higher.
Seems the story is where the alleged value lies, not the hardware, and the story is unique and interesting as some collectors find it to be. No doubt the $8500 price won't be too high for a collector who likes the story.
FWIW