Original Rear Bumpers

[kcfirstbuild]

Is it possible to fix up my original rear bumper. On the right side it has rusted and bubbled up on the diamond plate. How odd will it look if I cut the section out and welded a new piece in place. I was planning to do that sand blast it and paint it grey. Does anyone know what color grey is close to original ? I have a picture of a bumper that is similar to mine, but I have not taken a picture of the problem area just yet .