Yes, Goncalo Alves...the standard wood used by S&W for most target stocks from approx. 1975 until the 1990s*. Although some GA was used on earlier Coke Bottle stocks along with Rosewood and some walnut in the late 1950s. I didn't see a s/n in your post, so your revolver could date anywhere from 1962-1982. The exact style of target stocks (plain/smooth, diamond center checkered, or checkered) would depend upon when your 29-2 was manufactured.
*"SCSW 4 Ed.", "Extras That Affect Value- S&W Stocks", pg 38
*"SCSW 4 Ed.", "Extras That Affect Value- S&W Stocks", pg 38