To me, replacing the scales on a G-10 Delica or Endura, or a CF Stretch, would be easy. Full liners, all screw construction, and only simple round holes needed for clip mounting. Anything that involves drilling out pins would be a few notches higher on my degree of difficulty scale. Assuming I wanted to retain it, neatly creating the two grooves for a wire clip in one of the new scales would boost that up another few notches. Beyond that, I recall Sal once explaining that the reason the Calys are partially pinned is because screws would need to be larger in diameter and the larger holes that would necessitate in the lockbar and spring carrier/backspacer would weaken those parts, so finding replacement pins might be a better option. Personally, I'd look at the CF version or the bolstered CF Caly 3 if I wanted something classier looking than peel-ply G-10.