Surprised to find this clamp on Amazon at a very reasonable price. On a well known UK site it is over £30 including delivery.

Although I have checked the timing is correct to the book the book was made over 30 years ago ….. the burning properties of petrol has probably changed a bit since then.

Many tuners will say to advance the timing to when it just starts to pink when labouring slightly up hill and then retard slightly. It made a big improvement to the way my MGB performed so maybe worth a try.
