I've always thought that the 59's grips were a bit on the chintzy side (although I understand the ergonomic imperative behind having made them as thin as possible). So recently I bought these Thai grips, which turn out to be just thick enough that the gun no longer fits in its box. I'd prefer that they were walnut, but otherwise they're very nicely made, fit without any fuss, and as a 39 fan, for me they improve the look and feel of that gun's "big brother".