OP, your grips are made of "Goncalo Alves" wood and are OEM "Combat-Grips" from circa 1985' or so... They run about $350 to $400Plus on eBay... Ask me how I know!
I find them very ergonomic for my big mitts, beautiful, and with the right slim-fit gloves soak up recoil nicely into the meat of the palms, wrists, and forearms. They also allow for nice carry as they won't give away, bunch up your "cover garment/shirt" either.
Both OEM Smith's and Culina's versions are very nice for both display/beauty AND shoot well for me and are all I'll have/carry/shoot on an "N-Frame" Revo!
My favorite set I scored from a great member here below on my M24-3 Lew Horton Special in my favorite caliber the beloved .44Special...
Also, the "Flat-Sided" "Combats" made of Pau-Ferro (Bolivian Rose Wood) Combat's shoot very well for me too and carry even a bit better/closer to the side or haunches for me... Also very desirable and run $300+ per set on eBay/other sites as well from my experience. I have an extra set or two sitting in the safe for that next near perfect "N" frame I may come across that may need a set to complete the package.
To each their own, either you love em' or hate em. They have a following and that is a fact. You came across a nice set so enjoy em'...
Pic below of some of my favorites on other "N's" I love and have acquired of the years...