A quick answer, if you're referring to original items, is that Kearsarge grips used great quality walnut, while Ropers are pretty mundane. Looks like the guy who made the ropers, Gagne, just went to his local saw mill and bought a few walnut boards. Its like comparing the wood on Browning high grade rifles to the wood used on war vintage M1s. Roper used walnut, but its not pretty.
There aren't many folks here with Kearsarge grips. I bought a set of N frame grips because they were the nicest set of grips I'd ever seen up until that time. After I had them for a few years Smithnut, a poster here, put a picture up on the forum of a set. Turns out they came from one of his friends, and It might be Mike Priwar who had them. Then a few years later a guy from up east managed to do an astounding feat. He found a couple sets, one even for a K frame.
What Keith Brown has done was borrow my grips and took measurements. He then began producing very good replicas. Keith isn't afraid to buy and use fine quality walnut. He seems to realize the cost of the wood is a very minor component in the cost when you consdier how much time and effort he needs to use. Keith appears at almost all the OGCA shows (one coming up this weekend) and can usually be found huddling with "Pizza Man" on some grip deal. )
I'm going to guess I left out the idea that Ropers contribution to the art form was his use of drawings to modify each set of grips. He required his customers to trace their hand on a sheet of paper as part of their order process. I guess he modified the circumference of his grips to fit the hand of the person. I don't think we know enough about Kearsarge to know. But the one set I have fits my hands and eyes just fine!
