I wouldn't worry too much about keeping the car original. I have always said they are a good looking car that beg to be made better mechanically in most every way. LOL. When we cut the shock towers in mine, it was replaced with flat metal plate. Might be 1/8th inch. It looks pretty jarring. Since then I have seen shock towers cut by simply taking a vertical slice and moving the original contour in. That looks much more natural. Then simply bridge the gap at the bottom with metal formed to a 45 degree angle to get where the upper A-arms need to stay, if keeping those, back to the new location.