Considering all the "things" that you found, I would dismantle the entire front end and start from scratch. I have been there and done that. Found 9 cracks after cleaning all the crud around the "K" member.
I see.
Being that old I would confirm all of the welds have no cracks.
My 75 Swinger had 9 cracks after cleaning all the crud off. Hence the reason I had my K member cracks welded, plus the complete perimeter.