Frame rail pics

This needs to be replaced. It looks like it also has a slight bend to it as it doglegs down toward the torsion bar crossmember. Is this after you've been poking at the frame with a screwdriver? If its not, there may not be much of anything left to weld a cap to.

Taking the front end off isn't too terribly difficult. Once the torsion bars are out you can just unbolt the upper control arms, shocks, wires, steering column, and the K-frame bolts and it will drop right out. A competent frame repair shop should be able to easily replace that front frame rail.