My oh my, this one I am finding practically impenetrable. Close to an hour of head-scratching thus far, and making very little headway. I was brought up in 7d while it was still called that, so very much in my knowledge base!! And I found 11a quite clever and amusing. I have managed a smattering of other answers on the right side of the grid, building on from these, but wow I think this crossword is too hard!!!!