Bad Stainless Means Leaks!

[Springfield Acer]

I noticed on my first fill last Saturday that I had what looked like three seepers making very slow drips off the headers of my preheater. Now that the sap as dried up, I decided to investigate. I found five spots out on the open SS sheet with what looked like rust bloom and they all leaked. When I wire brushed them, they turned into pissers. On top of that, I found four more very slight seepers in solder joints. These leaks were showing up with just a complete fill up and standing on end for about 3' standing head pressure. I did not pressurize any further, half out of fear of more leaks but more because I did not feel the tanks could take it. The bad spots in the stainless look like some type of inclusion. I'm guessing that the acid in the solder flux just ate it out and left the hole.
I have successfully soldered them over and am moving forward.
Pix attached.88938894