[sick472]

Your wet spots by the welds may be seepage, that could very well be. Same at the tubes, but they might just be oils coming back out of the joints/porosity that seeped "in" from the outside at some point and is now working back out. Either way, it's not much to worry about. Make sure you spray down with brake parts cleaner right before you prime and paint so that the paint sticks. Heck, the paint may be enough to seal it up.