Hi Odin,
What makes it special? I know sometimes different companies use odd lengths, to try and make you buy the part from them. Is it cogged on the inside? If so then you can just replace it with a smooth one.
The company I use for belts, seals and bearings is
Simply Bearings and they have a page for V belts - it's usually just a case of measuring width, height and length and they should be able to help. ( I have a suspicion I'm teaching you to suck eggs about belts though! ).
The other thing I have come across is companies using odd length belts - you can usually overcome this by taking the tensioner right out which brings it into a standard range.
Dan.
Edited to addHere's the direct link to the V belt page
V belts