I bought this boat today it is a 1987 lowe river jon. The previous owner swore the boat never leaked once I got home a flipped the hull over I found three small pinholes in the very back. Im concerned that guythe foam in back has gotten wet and has now some severe corrosion I had hoped to put a 9.9 on back but now im kind of nervous to be pushing the boat hard.I took a auto punch and poked around the holes to see how soft they were they did make a indention but never went through.Does anyone have some suggestions