Monsal trail is open to the public anyway since it's in a national park.
Chatsworth park seems to have some public roads leading through it, and I think the owners of these estates have some sort of obligation to provide access, even if they don't advertise it (at Blenheim Palace in Oxfordshire there is a 'secret' gate that gives you free access to the grounds).
Worst of all, their claim about 'exclusive access' to Cromford
Mills is cr@p: it's free to visit the site anyway!
So it sounds to me like they are just puffing up some stuff that is either freely accessible anyway or which has equivalent routes through it. What a load of chancers...
And calling the routes 'our own strade bianchi' is a steaming pile of horsesh!t. The strade bianchi of L'Eroica are unique and have a definite connection to cycling, being the remnants of roads like the ones that people like Coppi, Bartali, Magni, Anquetil and so on would have ridden on.
There are some roads in the Uk that have some historic cycling connections (Box Hill, Shibden Wall, the cobbled road in Haworth that was ridden in the Tour of Britain in the 1950s etc), but the route chosen for L'Eroica Ripoffica doesn't seem to have any such connections.
It may be a nice route, but it's one you can enjoy for free yourself.