[snazzypig]

I would replace any line that is questionable. The clutch line has a rubber hose section that could have collapsed or deteriorated. You could take the old one to a place that makes hydraulic lines and fittings, or you could order a new one from
Inline Tube. I like to fabricate my own brake lines using Nicopp copper/nickel tubing. Advance Auto and possibly O'Reillys carries it. You would need a good quality double flaring tool and then practice to learn how to make good flared ends.