Best bet on the tank is to pull it. Put some moderately sized stones in it, seal the openings and shake the s**t out of it. If you get a lot of rust take it to a radiator shop and have them boil it out. As far as the lines go try carb cleaner and then blow out the lines. Visibly check the lines to make sure there are no rust out areas.

I am sure you will get other ideas on cleaning.