Hi Vic
I've just looked trough my copy of the Anatomy of the Ship of HMS Hood, and according to John Roberts it says:
Armament
Main: was originally to carry four twin 15inch Mk 1 mountings fitted in all British capital ships since the QE class but was redesigned after Jutland to meet demands of longer range. Hood was the only ship to carry the Mk 2 mountings differing from the Mk 1s as follows: elevation increased from 20degs to 30degs, 15ft rangefinders replaced with 30ft versions, and sighting hoods replaced with sighting ports (and a few other minor mods thats you won't be able to see).
Secondary: 12x 5.5inch BL Mk 1, two removed in 1938-39, all were removed in 1940
4x 4inch QF Mk V in single mountings- replaced by 4x twin 4inch QF MK XIX in 1939, increased to 7 mountings in 1940.
Anti-aircraft: 2x 8 barrelled 2pdr pom-poms were added in 1931 increasing to 3 mountings in 1937.
2x 4 barrelled 0.5inch MG guns were added in 1933 but increased to 4 mountings in 1937.
Torpedo: 2x 21inch submerged torpedo tubes which were removed in 1937, and 2x 21inch above water tubes.
As for superstructure changes, there were so many minor changes you would need to read the books to match up with the plans, books that document Hood's service life include
Anatomy of the Ship HMS Hood by John Roberts
The Battlecruiser HMS Hood: An Illustrated Biography 1916-1941 by Bruce Taylor
British Battleships 1919-1945 by RA Burt
The Battlecruiser HMS Hood Super Drawings in 3D No 23 by Stefan Draminski
Profile Morskie Drawings are available of Hood, as are Trumpeter's or Tamiya scale models of her in 1/700 and 1/350 scale and in either 1931 refit or 1941 refit.
Hope this helps, it would take me hours to copy word for word what is written in the book, it is a very good book with all the plans for every refit Hood had so it would be of some help to you.
The books are all commercially available via amazon or other retailers, and I believe that the Anatomy of the ship book has been revised and comes available as a paperback too.