Well, an update.
I splashed out on the 3M headlight polishing kit and have just spent an hour and half polishing the lenses up, previously have always used metal polish but probably not abrasive enough.
Its a bit worrying after using the first cut with 500grade on the electric drill, completely opaque finish, but very pleased with the results afterwards.
With the headlights on you can still see the crazing deep in the lens where presumably heat from the bulbs has caused crazing too deep inside the lens to actually polish, but nowhere near as cloudy finsih generally.
Have used a glass sealer on them and two coats of Bilt Hamber's wax, have ordered some CarPlan No1 Gloss from Amazon on the recommendation of TonyCL on t'other forum.
Hopefully the pics before and after will add to this
Not being David Bailey the pics aint great but hopefully show the improvement, if anyone asks which was the before/after pics i'll go boil my head.
As a bonus for those who like them here's two of our idiot doggies