I think it's a very one-sided challenge, loge. There are unclued entries, extra letters in some (only 'some' makes it harder too) of the wordplays and it's jigsaw entry! With so many tools in the setter's armoury the clues should have been crisp but there are superfluous words, wordy defs and wordplays with umpteen possibilities. I realised I'd have to progress in a 'leap of faith' manner, not something I ever find enjoyable.
Sorry, but for me, the end result hasn't justified the effort - although that part is at least reasonably straightforward, even if the instruction is rather vague (I'm just glad I guessed the right way regarding left/right grids).
nelson - go with the 'leap of faith' approach (unless you haven't abridged a 4 letter word!)