BLT78wagons

Everything is original from 78 The last time it was inspected and on the road was in 94

There looks to be a plug on the bottom of the Tank and does anyone know where to get a fuel level sender seal

10 year old fuel in tank trying anything t get line cleaned out inside any ideas or tips. It's on a 1978 subaru wagon 1600 I dont want to remove the tank

http://s1318.photobucket.com/user/brandon_thomas9/media/Mobile%20Uploads/20160228_111842_zpsucghbbaf.jpg.html?sort=3&o=3

I have both engines running and was driving down a road and saw them. I'm stuck because there is 10 year old fuel in the tank and I can't get it out. It's all gummed inside anyone know where to get a gasket for the fuel level sender

I need help I found two wagons in hershy pa. They both sat since 2009 and everything seems to be there just didn't know what would be the first step to get them running and what do I need to know.