I purchased one last year for my own set due to this problem for £170 but I noticed it had a small chip in the glass and eventually obtained a replacement and still have the one with the chip if you want it as the company didn't want it back and I didn't like throwing away a new tube. You would have to organise the collection though. It is still in the box and working o.k as I initially installed it before I noticed the chip and then checked the bottom of the box and found a tear as though a forklift had burst it.
sparky, November 2005