There are some definite downsides to "dovetailed" bolsters also. If the scales are *really* insisting on warping (some horn is horrible about warping), being trapped by the bolsters can cause the thin liners to warp also, since the scale material has no place to go and puts all its force against the bolsters and liners. If scale material shrinks significantly, dovetailed bolsters may hide this a bit, but it also exposes the sharp feeling edges of the bolsters, which I personally really dislike. If you haft the scales like they did in most fine antique knives (scales were not normally left flat, but fully rounded and shaped to fit the hand - thicker at the center, considerably thinner at the edges of the handle), then with dovetailed bolsters you wind up with an arc/curve where the bolster meets the scales - depending on your sense of aesthetics - especially if you love the looks of the old original knives - this may not appeal to you.
Of some possible interest, many antique knives do not actually have a 90 degree bolster-scale fit at the liners -- the bolster and scale are actually fitted at a bit of an angle in what might be called a reverse dovetail - the scale material actually *overlays* the bolster a little. This is not sloppy workmanship or fitting - this was done on purpose. There are several advantages - first, this also hides scale shrinkage somewhat - but exposes no sharp edges at the bolster; second, it was a visual guide for proper shaping and hafting of the scale by hand -- scales were also often tapered in thickness - thinnest at the bolsters, thickest either at the center of the scale or at the head end (depending on the pattern of course). When properly done, the bolster and scale will meet at the *top* of the thickness tapered scale at a 90 degree angle - which was rather obvious to the eye as looking "right" when they were hand hafting these things way back.
