Note that there are numbered clues for all entries, yet the preamble gives wordplay for ten more entries. I am finding that the preamble wordplay answers replace some of the clued answers in the grid.
The ten entries are all thematic anagrams, although most are pretty obscure though.....and the additional/missing/correct letters are a beast to work out ! Definitely the most difficult this year so far.
1a is thematic. The clue refers to a type of watch, rather than to look at. 1d the definition has a letter change to d. It is a derogatory Canadian word. Hope this helps.