I have a 4 gallon natural Clarke tank that was taken off of my '17 390RR-S. I bought it to use for longer trips (Moab/Baja etc). Those aren't happening and I have a 3 gallon installed instead for riding tight single track.
Tank does have scuffs and comes with a cap. You will need to lengthen your fuel line (approx 12") to make this fit correctly as the connection on this tank is up and forward compared to stock. I can send the extra fuel line with if you want it.
I do NOT have the bracket that originally came with the Clarke tank that holds it in place on the frame at the top front. I am the second owner.
$150 shipped in lower 48.