To weld on slide or not ?

This old Remington Rand slide had a clark rail installed on it.  The holes were drilled off center. Was thinking of tig welding the holes up and relocating them. Is this a good idea? I'm worried about making the slide soft or warping it. Any advise?

A High Master in my area actually had his scope rings welded onto the slide.  It can be done.

Chances are your slide is already soft.  A good tig won't do any damage.  Just make sure you let your welder know you have to have it drilled and tapped again.