SCS&W III, page 202, has a photo of 3 M-29's, one an 8-3/8" with the scope ring cuts on the barrel and wearing the square butt finger groove "Combat" S&W grips under discussion.
The Classic Hunter M-29's (6 inch full-lug barrel, 4 position adjustable front sight, non-fluted cylinder), like ME109's beauty above, came with Hogue rubber grips, at least mine did. His grips shown are a good example of what we are talking about here.