Chris doesn't work at Brooklands anymore. he has gone alone and started his own company (sort of) called Torque of the Devil, which is just down the road from PE.
I am not sure if he is up and running yet but he is/ will be getting a 4x4 Dyno Dynamics dyno. That would be where I would be taking my car if I wanted an accurate BHP measurement. If I wanted to flatter my ego I would to PE