I need a replacement pair of headset bearings, the old ones are labelled TANGE SEIKI 4T5-5 BEARING which I'm pretty sure means they are campagnolo standard (45 degree upper and lower) rather than the more common 36/45 degree ones. However I can't find anywhere with any of these in stock.

Does anyone know where I could get a set of these?

http://www.parker-international.co.uk/14265/Tifosi-1-1-8–Headset–Campag-Fit-.html

http://www.sutherlandsbicycle.com/Chapter12.pdf

I bought one of these for my commencal.It's worked well for the last few months.
http://cgi.ebay.co.uk/Stolen-Insider-45-45-Headset-3-Colours-/200462175294?cmd=ViewItem&pt=UK_sportsleisure_cycling_bikeparts_SR&var=&hash=item746a8d4784

Thanks for the links, bizarrely I popped in to my LBS this morning, they had FSA campy compatible 45/45 headset bearings, but they had a larger outside diameter (by about 1mm) and much larger chamfers. So I now have no idea at all what I need as replacements.

In the end I've ordered a pair of these:
Cane Creek Bearings

They look about right in the picture…. just have to wait and see when they turn up.