Summary so far.

A - Admiral Benbow
B - Bold Fisherman
C - Cutty Wren
D - Death And The Lady
E - Earl Of Murray
F - Finnegan's Wake
G - ??
H - Hearts Of Oak
I - I Wish I were Single Again
J - Johnny Todd
K - Keeper Of The Eddystone Light
L - Lady Franklin's Lament (Lord Franklin)
M - ??
N - Navvy Boots
O - Oh Joe, The Boat's Going Over
P - Poor Old Horse
Q - Queen of Hearts
R - Ring The Bell, Watchman
S - Six Dukes Went A-Fishing
T - Tarry Trousers
U - Unquiet Grave
V - Villikins And His Dinah
W - Woodland Revels
X - ??
Y - (usually called) Young Roger Esquire
Z - Zip A Dee Doo Dah

Just G, M and X left. Doing well ... anyone got any ideas for these three?

:-)