[Healeys] 100 Service Manual trivia query

[Bob]

Does anyone know how many 100 service manual version there are?

I have:  Sept 1954 # 997B
             Sept  1956  # 997C
             Sept  1956  # 97H997D
                       1959  # AKD4851  (No month given)

Is it a reasonable assumption that there was an original or A version prior to 
Sept 54?

Anything between 1956 and 1959?

Thanks,

Bob
55 BN1