Pipes can be bought seperately with o rings fitted from MB,o rings kits are available on ebay made from viton which is remarked as being longer lasting than the original rubber.I replaced all of mine, as i was of the opinion that one was leaking than others were sure to be in a similar condition.I removed the inlet manifold for better access.
The fuel shut off valve also developed a leak which was through body not a seal,the cost of this item was £115,hoses range in price from £5 to £8.
Once all hoses fitted it showed up my battery was useless because it did not have the charge to keep turning the engine over long enough to purge the lines of air.