Without a doubt the USN colo(u)r here would be different to the Royal Navy colour, going only by the red pigment.
It's worth pointing out that the British used two distinct blue-black pastes and it might be worth asking Michael to remind us which one this formula used (I suspect Admiralty Pattern 370A)...
A single 7lb can of Admiralty Pattern 370A Blue-black paste turned 77lb of white pigment oil paste to Home Fleet Grey (Admiralty Pattern 507B, or Admiralty Pattern 507A, or G10) colour.
A single 7lb can of Admiralty Pattern 371 Blue-black paste turned 78lb of white pigment oil oil paste to Mediterranean Grey (Admiralty Pattern 507C, or G45) colour. This paste was also used in colours B15 (a double shot, plus a lot of pure ultramarine), B30 (just shy of a triple shot) and B55 (a partial can).
Clearly Admiralty Pattern 370A is much stronger staining than Admiralty Pattern 371. Whilst of tangential interest here, it's worth point out that blue-black paste can have significant differences in its influence depending on inert pigment extenders which must be present in AP371 to bulk it up to a stiff paste but such that the whole can makes a light grey out of a basically similar volume of white base.
The inference here is that we cannot assume parity between whichever of the RN's blue-black pastes is used here and the USN's blue-black paste. Even the choice of black pigment used can have a greater or lesser effect, and when such a small weight of black and ultramarine pigment has such a drastic effect on a large white weight, selection and proportions of the specific black pigment and the proportions of ultramarine to black are critical in arriving at a vaguely similar shade.
The red however is instructive. There is simply much more of it in the British paint.
There's a bit of an inconvenient incompatibility with composition here in that as you know the USN 5-x paints were made by adding pints of 5-TMa blue-black paste to 5 gallons of 5-Ua untinted white base.
Zinc white paint has a density of approximately 1.4 x that of water. 5 US gallons of water weighs approx. 42lbs. 5 US gallons of white paint therefore should weigh in around 59lb, but it will be weaker than British stiff oil paste, to which further oil and thinners would be added. A pint of water weighs roughly a pound, so we should probably boost up the assumed weight of 5-TMa also. Ultimately this might get us to an appearance a bit lighter that 5-H, which should have 2 pints of 5-TMa to 5 gallons of 5-Ua.
I imagine the American formula above would result in something a bit like this, if my assumptions about the behaviour and characteristics of the American base ingredients are correct (I may need to reconsider this if they're not - it's not an area I'm strong in):