Finished, earlier than often, and before coming to this forum.
I enjoyed the multi-homophone setup: 9 was FOI, and we solved 16 fairly soon, so when I cracked 21 I tried saying them out loud ... and started looking for a composer of forename x or y, which differed only in their 2nd letter, although the answer, which Google offered me, turned out to have different 4th letter.
Got stuck on 10 as i didn't think of the right Hamilton but googling gave me a couple of bands and a Louis Armstrong song for my wrong solution which fitted 4 crossers and made it impossible to solve 5d.
Eventually took the 4 crossers to CrosswordSolver and found the right Hamilton!
LOI: 5d
COD: The whole punny 1a etc complex, but I also like the simple elegance of 27a.