I buy the fuel line and end furules from Geoff Ohland at Partsource. He sell it to Ferrari restoration shops. He is not happy selling to individuals, as the assembly of this type of line can represent a fire hazard.
The original line was fabric, laid up with lacquer. This line literally comes apart with modern fuels. Various additives in modern fuel dissolve the binders causing the line to leak with resultant serious fire risk.
The new line is manufactured for the vintage aircraft industry and is VERY expensive, so much so, it is sold by the mm! The appearance of the new "fuel-proof" line is very similar to the older version, except the O.D. is slightly larger, and it uses steel end fittings rather than the original aluminum.
Partsource will sell this new line to those that can assemble it in a manner to avoid leaks at the fittings. This is for liability reasons. He does not wish to sell it to individuals.
When I build a fuel line for my Alfa customers, I charge ONLY for materials, plating, shipping, and a nominal $25 cleaning charge. This is essentially a free service on my part, as I make NO GUARANTEE as to a leak proof assembly. Thus far, NONE I've built, and in service, have ever leaked, but as a liability protection, I cannot offer a guarantee.
Below is a restored line, recently completed for Keith Goring at Alfas Unlimited. This assembly is for a pair of 1960 40DCOE2's. My charge for the assembly was $125.00 less shipping and plating.
I believe I've posted other information on this fuel line, here on the BB. Imagine what the cost of materials would be for the Ferrari 330 or 275 owner. About 12 FEET of this line are used on those cars!