Do you want the shorter line that exits the fuel pump to the filter, or the longer one, from the filter (located behind the alternator, more or less) up to the carburetor? I think I have a spare shorter line.
The aftermarket ones are pretty decent, and worth the (<$50) cost if you want it looking original and pretty.
https://www.classicindustries.com/product/1970/plymouth/cuda/parts/mf573a.html
Years ago, I bent my own, upper line, using some 5/16 steel (brake?) line I got at the auto parts store. The 3-foot length even came with the correct brass fitting and already flared at one end. All I had to do was bend it, cut it to length, and add the partial flair for the rubber tubing. I purchase a flair tool and this foot-long anti-crimp spring to help me bend the line. I imitated a photo of an original line (like the one above) and it came out really nice.