According to the manual there are 4 fuel lines. But the linked post mentions a balance pipe which I can't find in the diagram.
I've not had the tank off yet and don't want to f*ck up!
Two are breathers - well one is drain from tank filler, other is breather. They are thinner and can be separated just at rear of tank where they are joined by white plastic fittings. Other two are fuel feed and return which are 8mm ID pipe (so you need QD fittings with 8mm spigots) The GSA tank has a link pipe which is 6mmID I believe.
I just used plastic ones from ebay or somewhere, but might replace them with metal ones one day