Since that book is rather short, probably 80-100k words at most I doubt your notes are anywhere near that long, if they exist at all.
Equivalent notes for a Harry Turtledove novel or The Domination of the Draka would top 100k and be novel in themselves.
That was bloody rude Timmy.
I think your estimate of the length of Britannia's Fist is about right. It is however such a staggeringly bad book that there is so much to write about. Consider the following:
The book is extremely jingoistic if not racist,
the author cannot separate his views from those of his characters,
the standard of English is very poor,
the editing is very poor,
the primary justification for the story is logically inconsistent,
there is an huge amount of what I can only consider to be unintentional homoeroticism in the book which is the only funny bit in the book
there is no PoD, there is no clearly defined set of PoDs history is simply rewritten to meet the author's need.
it is not possible to determine when the author is being ahistorical and when he is historical at the start of the book
the author's anti-Marx views suggest a lack of scholarship on his part given the impact of Marx on the view of the ACW in Britain
the author's characterisations of British characters, French characters, Russian characters and indeed everyone except Union characters is offensive to the point of characature,
the author cocks up British names,
the author cocks up British diplomacy and politics
the author does not understand any ballistics (and this is an ex tank officer!) his understanding of the performance of Dahlgren and Armstrong guns is so pathetic as to be pityable.
the author does not understand armour plate to the extent that he cannot distinguish between wrought iron and steel,
the author does not understand ship stability
the author has used the Royal Navy of 1862 in his story not the appropriate Royal Navy
the author does not understand that a ship on coast guard service is not fit for the deep sea
the author overloads the USS Gettysburg to the point that it would sink
the author claims unattainable speeds fo US ships
the author cannot tell shot from shell
the author garrisoned the wrong forts a Portland
the battle at Portland contains physical impossibilities
the battle of Portland require that a British post Captain act like a petulant five year old
the battle at Charleston is physically impossible and could not have happened for any number reasons
the battle at Charleston is unrealistic in both the Union defence and the British response.
the intervention of the Russian admiral in the chase would have been regarded as treasonable by his superiors
ach! I grow weary this is just under half the things I have notes about are you truely surprised it reached 20,000 words?
As to Turtledove I have never felt the need to take one of his books to bits and I don't enjoy the Draka books so I have only read two of them and again I never felt the need to pull them apart.