I know this thread's a few months old, but...
How is the RR classic box different from a standard 4 bolt adwest?
What i mean is, ive heard of people using defender boxs, but you mention the RR specifically, and they both look (from my 5 mins looking) to be the same, so... (?)
Id like to do a conversion on mine, but its LHD, and, whilst RHD boxes are easy to come by, ive not stumbled upon a LHD yet.
Although someone did say that the RHD london taxis, possibly, used the same part as LHD defenders... but i dont know if that was true or not.