I scrape with a plain steel scraper, with the edge simply filed (I have never cared to bother with all that burnishing and rolling a hook... and then have to take care of it??? I'm way too clumsy and hard on tools for that to last very long.) I just use a straight, rectangular one, and one that has one end in a large radius convex curve. This curve is for getting into areas like the cheekpiece or nose of the comb. Simply rotate the scraper to change the "radius" of the cut. The only glass I use is a ground glass microscope slide, which is very good at doing the final FINE light scraping of the stock. No, you do not want to try to hog off a bunch of wood with it, as it will chip and scratch the stock.
"Ripples" are easy to avoid, I don't really see them on old guns, so I don't try to "imitate" a rippled curly stock finish. Simply angle your scraper to cross diagonally across the curl and zero ripples.
What I DO see on old guns are scratches, flats, facets, and more scratches. I do try to get rid of these on my guns, BUT sometimes (often) they just show up after you have finished it! They generally did not worry THAT much about it 200+ years ago, from what I have seen. Now, certainly, I have seen old guns here and there that were REALLY smooth, but that seems to be the exception to the rule.
I have one old German bird gun from probably the 1720's that I really learned a lot from. When I got it, it had absolutely NO trace of finish of any kind on it... like clean dry wood. Well, not really clean..... The pores were even open except for the DIRT that was in it!
I probably shouldn't have, but I did rub some wax on it just so it would look like something and not so dry and dirty looking. I would hate to even hazard a guess at what it was originally finished with... Maybe quickly rubbed with a couple of light, thin coats of linseed oil (not anywhere near enough to fill the grain)
A quick shellac on the surface that has long since simply flaked off???
At any rate, the wood surface is marvelously original. It is obvious that it has never been sanded down. The carving is worn on the fore end and on the top of the wrist where hand have handled it, but that's about it. It was used, but not abused. It is stocked in the Spanish style, with the heavy stepped wrist, and fluted/moulded butt. Scraper scratches are quite evident in all the carved flutes on the butt. The wrist was most interesting. It is not really round, but it is made up of lots and lots of tiny facets created when the smith ran his scraper down the wrist!
This is the type of thing I like to do on my guns (well... maybe fewer scratches!) and what I like seeing on other modern-made flintlocks.