nice refurb! you need to wet sand the tank to get it clear like new.
so wet sand 1500 to 2000 or the highest you can get then buff and
polish with novus. the end result will have your tank looking like new.
if 1500 to 2000+ doesnt work you'll need to work from a lower grit
paper but it looks ok so starting at 1500 should be fine but you can
start with 1000 then 1500 to 2000 and so on if you want.