Karl,
I literally JUST walked in the door from Vienna where I travelled with my band, the Fairey FP (music) Band. We took 2 EEb's and 2 BBb's and had no problems with getting them on the plane (in the standard Boosey cases). I think they were trying to charge us in Vienna this morning when we left, but as far as I know, leaving from Manchester was no problem.
35 kg (approx 70 lbs) is the standard limit, but when I fly BMI, they are more relaxed as it's a musical instrument. I got nailed with fines flying out of Dulles, but not whilst in the UK.
I hope to be back in Sept for the Open, so we'll have to meet up for a proper pint if I am!
All the best,
Josh Wirt