Actually from my experience your front rails do not look that bad. Certainly probe them when checking them out. If pretty good I would spray a mixture of grease and oil into them. Generally after that they will not deteriate or at such a slow rate the rest of the car will disinegrate prior to any trouble from them. They of course gain their strength from the shape the metal is punch pressed into while not having particular great strength over a small load bearing area and as previously mentioned they bend and deform a little even if in good condition if load is not spread when car is jacked up at or resting on them.