Thank you so much Grahamderek, malone and eider. I had "Unst" and "anna" (short for annatto") which prevented me seeing it. What a fool I am. I should have trusted that 46a was in the grid for a reason. Very much appreciated!
I thoroughly enjoyed this, thank you Elpenor! My only problem is that my answer to 24A ( In retreat oddly missing vigor (4)) ends up being a rather rude word with no connection to the clue that I can see! Any help please?