This is a real decent old BSA gas tank.  It is rust free inside.  Could use a good flushing out. It comes complete with the petcocks, gas cap and rubber mount in front. It looks to be an original red tank that had been painted blue.  The chrome is decent for its age, but it does have pepper like spots in the chrome, that are kind of hard to see in the pictures. You can see them if you look very close in the pictures. They can be seen alot easier in person. You could repaint this tank and it would be a very nice tank for a rider.  If you are doing a concourse restoration, you would have to have this tank re-chromed.