New tube for Portaflash 336VM

Hi All,
I'm trying to get a new flash tube for a portaflash 336VM and was wondering if anyone knew where to get one, or what the spec for the tube is so I can look around.
To be clear it's not the screw in modelling bulb I need, it's the actual circular tube. I don't think it's supposed to be user replaceable and Jessops can't help.
I have looked on ebay, I thought I had seen one on there but I can't see any at the moment.
Any ideas?
Thanks,
Michael
I'm trying to get a new flash tube for a portaflash 336VM and was wondering if anyone knew where to get one, or what the spec for the tube is so I can look around.
To be clear it's not the screw in modelling bulb I need, it's the actual circular tube. I don't think it's supposed to be user replaceable and Jessops can't help.
I have looked on ebay, I thought I had seen one on there but I can't see any at the moment.
Any ideas?
Thanks,
Michael

Thanks for the answers.
I bought the faulty unit on ebay as part of a job lot (2 of the 336VM's, stands, and a few other bits and pieces). It was marked as being faulty but I only really wanted 1 of them to add to add to my existing kit and for £40 for all of it, it was well worth getting.
Now that it has been sat for a while I thought it would be good to try and get it going, if I can't I haven't lost anything.
A friend is a bit of an electronics wizz and has got the unit open. While the tube is not supposed to be user replaceable he thinks he can solder a new tube in and get it working for me, all we need to know is the voltage / wattage etc to get a new one.
Jessops can't help. The guy I spoke to at there customer support told me to look on the manufacturers website, he didn't even know it was there own brand!
I'll keep looking, as I say I have nothing to lose.
I bought the faulty unit on ebay as part of a job lot (2 of the 336VM's, stands, and a few other bits and pieces). It was marked as being faulty but I only really wanted 1 of them to add to add to my existing kit and for £40 for all of it, it was well worth getting.
Now that it has been sat for a while I thought it would be good to try and get it going, if I can't I haven't lost anything.
A friend is a bit of an electronics wizz and has got the unit open. While the tube is not supposed to be user replaceable he thinks he can solder a new tube in and get it working for me, all we need to know is the voltage / wattage etc to get a new one.
Jessops can't help. The guy I spoke to at there customer support told me to look on the manufacturers website, he didn't even know it was there own brand!
I'll keep looking, as I say I have nothing to lose.