That looks stunning, really nice on those wheels! Why the need the change them for the RR though Martin?
Some Ripley wheels would be stunning definately!
Dyno's dont do sticky track or even a softer compound road tyre. The rubber breaks up due to the heat put through them running on a small surface area for a long period. The tyre ends up rolling on small beads of shreaded tyre and thus makes the car loose traction on the rollers. Also can damage/wear the knurled surface of the roller.
A good high end road tyre Pirreli etc are whats needed to record all the power for graphs on a dyno.