Restoring a Pontiac for a customer... Not very well versed in what's ok and not ok to do to an oldie like this... The front fenders need some cracks welded that are right on the seam... someone has previously welded about 8 inches of the seam together on the passenger side fender... will I get totally blasted if i weld the entire seam and body work it or is this one of those things that will drastically hurt the value or....???