Your temps are pretty good as-is, and you probably have a fairly decent chip, I need to run mine at 1.32V top get 4.9GHz stable and consequently it runs hotter than yours.
I'd say it's only worth delidding if you want to push a higher overclock. If 4.9GHz is stable at 1.26V then your chip will almost certainly do 5.0GHz, and you might be able to get up to 5.1 if you're willing to push up to 1.4V. If you're happy with 4.9GHz then just leave it as-is.