Mistydowns.
I'm looking into it. I want to check the following on my rose that pertain to Camnethan Cherry Red: "PEDICEL: glandular and prickly.
SEPALS: Glandular
RECEPTACLE: Small, slender cup, a few glands, more at base
HIP: Small, globular, orange, ageing to brown
FOLIAGE: New: bronze-red. Old: dark green.
PRICKLES: Moderate to sparse"

My 'Beauty of Rosmawr' shows a lot of variation in the appearance of blooms. One variant looks a lot like blooms in other users' gardens. Others look less similar. Looking at images of Camnethan Cherry Red' I can see one strong point of difference: on my rose you never see yellow stamens. The innermost petals invariably curve inward and shield the stamens from view. The bloom disintegrates without ever opening out so far as 'Camnethan Cherry Red'. This is notable because that was once a prerequisite for residency in my garden (immunity is granted to Dainty Bess because its stamens are red, and i'm not sure how Sadler's Wells, Rugspin and Scabrosa get away with it, though they do :)).
I'll report back when I have more info to offer.

I think my 'Beauty of Rosmawr' IS the one that Mistydowns are selling as 'Cammnethan House Red' (sic), if one photo can confirm it. My rose looks like the Professeur Ganaviat images posted by Jedmar, and not so much like those posted by Marcir, Gartenjockels kleine gaerten or Rita Rose.
It also looks to me quite dissimilar from Princess de Sagan.
I do not think it looks much like any of the images of Camnethan Cherry red that have been posted with the possible exception of Eric Timewell's. Looking at Margaret Furness's whole plant, the blooms are upright. Mine often tend to nod. My rose's blooms are limp, petals fewer; the whole effect a lot less 'full' than those in images here of Camnethan Cherry Red, and mine's blooms are not so red. They are more magenta to light crimson. Still, my plant is as Billy T has described Camnethan Cherry Red: 'sparse and airy', though the fact that it's not very well-lit could also have something to do with that.
I am still yet to check pedicels, sepals, prickals etc. The plant is 2 or 3 years old and is 2 m tall.
If only the plot were whipping cream. Then its thickness would at least make for a decent pav.