Hi David
not been on website for a while, there is an article in this months Enjoying MG (MGOC club magazine) about refurbishing the MGF headlamps and using Dual metalising for the recoating. yes they have to be dismantled with extreme care, as replacement glasses are expensive and new light unit are around £185 each! the reccomendation is to buy some lights on ebay or breakers and refurbish these, because its a slow job and the car needs to be off the road for about two weeks. presume you know that the front bumper has to be removed to get the headlamps out, the MGOC have also written about this procedure. ther are some very interesting and informative articles on the internet on this subject ~ Google MGF Headlamps.
Regards
Bryan