Loosely speaking, there were 2,500 Roadsters made.
There are currently 49 Roadsters registered in the UK although as far as I know around 70+ were sold here.
There's only a few RHD countries where they were sold:- UK, Japan, Hong Kong, Australia. Although there's at least one in New Zealand because I've seen it - an amazing looking green one, and there's bound to be a few other places where they've ended up as imports.
I would have thought there's little more than 20-30 in each of the other RHD territories but I have no way of verifying that. I know we have a few HK members on the forum - perhaps they can chime in on this ?
Overall, I'd suggest the ratio of LHD / RHD is around 12:1.