Is this frame toast?

So I found these lovelies on both frame rails at the shock towers:
(driver's side frame rail side toward engine)

(passenger side top of frame rail at shock tower)


The frame has already been patched at the firewall (driver's side), so should I plan a complete frame rail replacement? I have located a complete frame rail and inner fenders from a Valiant that's in much better shape than mine. How difficult is this swap for a novice or should I contact a professional? Thanks!