Could be the feed hose or the return hose at the tank with fuel running down the steel pipes to the low point near the rear wheel; but, the most likely situation is the steel fuel pipe/s are rusted out, usually in the area where they pass through the rubber grommets which are held in place under steel clamps. A combination of corrosion and abrasion usually, water/salt/grime get trapped between the grommet and the steel pipe, after 20 years the coating wears through and then the steel.

Off hand I can't recall the exact size fuel hose you'll need, I'm pretty certain the steel pipe is 8 mm OD if you can’t find metric dimensioned line, 5/16" ID will probably work, you'll only need a foot or two! Good luck!