Ret W4, I have the hideout grips made by Keith on my LH 24-3 and they fit perfectly without him needing to have the gun for fitment.
I bought my gun when these LH first came out and remember some gun press reporting that it had a K-frame round grip frame. Which, is not 100% true. Before I got my gun I thought it would be great with a set of RB magnas and a T-grip. I tried those magnas on when I got the gun and found what everyone else has - they don't fit at the top. Short of radically modifying the N frame, there is no way to fit K RB grips to this gun. But, the gun rags at the time perpetuated the myth of the K on an N frame. In the December 1984 issue of Guns & Ammo there is an article authored by Howard E. French about the LH model 24. On page 54, in a photo caption is written, in part: "The Smith and Wesson Model 24-3 is a non-standard sixgun. In that it combines the "N" frame .44 Special with the "K" frame round butt." In another caption on page 51 it states basically the same thing, describing how controllable the N frame is with a K frame round butt mated to it. They likely got that info from the Lew Horton advertisement. It would have been more accurate had they described it as a "K" frame like grip on an N frame. Really, it is a "N" frame round butt.
I read those articles with great anticipation while I was waiting to get the gun I ordered. Unfortunately, we all learned it was not true. But, KB to the rescue and now I have what I consider the best grip for me on this gun.