.120 to .100 is my target. I've measured a lot of originals. That is where they mostly fall. Not all are even. Some taper from the wedge to the pivot end. I stay .110 to .100 for the smaller blades and maybe .120 for the big 1 inch blades. Measure some originals. Getting over .120 even for large blades makes the scales look thick. Do a good job tapering the edges to the center of the scale. Don't just round over the edges. Again look at some originals.
Make sure you drill your pin holes before you start shaping the scale. The flat surface makes it easy to keep things centered.
.25?? that's 1/4 of an inch. Way thick.
See Glens advise.