Have had whole house rewired and electricians back filled chasing out but has been left rough and in places above wall level. I realise it needs levelling first but not sure how far to take it back below the wall surface and how to make good, what to use etc. Really am looking for advice which will save having to have whole room skimmed. Also on a couple of the kitchen sockets there are quite large gaps around the metal back boxes which need filling prior to making good is it bast just to fill these with mortar? Have put photos in album. Many thanks