Yesterday had too much on to post, but I fitted new Xenon bulbs and polished the lenses! Followed WIS in removing the headlamps, and I don't see how the garage could have made such a mess on Norfolk Jim's car.

It's not difficult, and providing you site the bulb between the fingers of the 'fly trap' they all make contact! The biggest headache was the length of free cable on the left hand lens meant I had to unplug it before I could get the bulb clear, then hold the new bulb above the fly trap whilst I plugged it in again.
By putting things back on the marks (a bit of dirt helps!) everything went back together neatly. I now have bright lights up front, much brighter and bluer than the old bulbs which had started to flicker, and no frosted patches to reduce the transmission.
Having read up on UV protection, tomorrow's task is to wash and wax the car then to wax the lenses, hopefully to reduce the rate of oxidation now that there is no UV coating remaining on them. (Not that I'm complaining on an 11 year old car.)