If anyone needs to repair a headlamp silvering this self adhesive Mylar works well
10M SILVER WHITE MYLAR SHEETING FOR HYDROPONICS | eBay
You just need to gently sand the old silvering smooth and de grease. Then apply the self adhesive as smooth as possible. Any wrinkles are un noticeable once the glass is back on and it's heat proof !
Hey presto - new looking head lamps that work well :-)
Just a quick fix that works well for a long time until the budget runs to expensive re silvering