To the best of my knowledge it was 2010 that they changed the reflectors. We have a couple of factory guides on here that maybe can help out with this one and the LHD question.
My best guess is that the owner saw these fitted to another car and had them put on at a later date as you correctly say they weren't on the options list back at the launch time.
It's always worth asking the question of the factory once they open up again.
Enjoy your kilometres I thoroughly enjoyed my Sport and covered 24,000 trouble free miles in it, arguably the purist Morgan ever built and I agree with that statement
