Thanks for all of the replies.
I'm using V30s atm, but I'm borrowing the standard Engl 4x10 cab, which apparently has more modern soudning speakers (have a complete mental block on what they are called).
Thanks for the suggestions of less gain, I'll give that a go first thing tomorrow and see how things sound.
I'll also try the EQ suggested and see how that sounds - "JackBauer" - thanks very much, if you do manage to nail the tone them please let me know - my search for it continues tommorrow!
I'll be having it re-valved soon, so I will consider the suggestion made about valve types too!
thanks again, Alex