You've done the easy part, now for the rest.When you are finished staining etc,when you're watching TV or have some time on your hands then just take the gun and rub it by hand especially the area from the rear pipe back and the butt and wrist in particular.Spend at least a half hour or so each time and you will be amazed how the wood will start to glow.I've also used nose grease on the tang surround and on each side of the guard. I have really hit the wrist and the forestock foward of the guard being the areas which are handled the most.I took an old French fusil that was literally in barn loft condition and a stock that was almost totally dried out, gently washed it with warm water, dove,and a soft cloth then when it was dry started hand rubbing with nothing but my hands and a little nose grease around the tang and guard and after about three months it looked like it had been in the house the last 100 years instead of a barn.I did this for about a year and when I get it back with a replacement lock, I'll keep on.I have another gun possibly from the same stock that was worse and I'm giving it the same treatment.French walnut has a really nice look to it and while old patina is hard to recreate it is possible to give come close with a lot of hand rubbing. I have also used Fiebing on walnut to touch up areas that need a little color before rubbing.By the way English walnut and French walnut are a lot closer to each other than either is to American black walnut.That's a little trivia I thought I'd toss in.Your gun looks a lot better now and with some hand rubbing it will get better.
Tom Patton