Hi Dev,
I've done a bit more investigation on Martin evans 21/2" gauge black five, it was described between 1984 – 1985 in the following issues:-
3728, 3730, 3732, 3734, 3736, 3738, 3740, 3742, 3744, 3746, 3748, 3750, 3752, 3757.
I trust the foregoing may be of assistance.
Regards,
Bob