I think there are a few more about than you might expect. i suspect there are about 4 or 5 roadworthy ones and 20 odd on sorn, plus a few that emerge from the woodwork and appear on ebay every so often as projects. there's a mint gold one that has appeared in practical classics which has the same CON suffix as mine and came from the same dealer and was supplied around the same time. I believe that was also a factory left hand drive car that got put beck to right hand drive before the dealer sold it, as mine was.
I'm quite close to finishing the back end of mine, i'm hoping to have another good session on it in the spring once i've got a bit more time.