There isn't much to the action area. With the action tightened into the stock, use a sharp pencil to trace out any areas where the wood is more than a pencil width proud of the metal. In the photos above, you can see I have a lot of work to do at the tang, and the rear trigger guard. All else is pretty close.

Don't sand too much around the cross bolt holes. The tolerances there are known to be uneven. We will take care of it when we fit the cross bolts later. for now, just knock the finish off as you work back.

NO MATTER WHAT, YOU MUST RESIST THE TEMPTATION TO USE ANY POWER TOOL...NO DETAIL SANDERS, NO DREMELS. Ask how I learned this lesson...ok I'll tell you. the first stock I fit I though...I have a steady enough hand. I'll use a Dremel to even out the pistol grip, I'll use 120 grit or finer on the the little spinny cylinder to rough it...then I spent days and days evening it out. It worked out, but my blood pressure was through the roof and I was a nervous wreck questioning every hour if I had ruined the stock. Trying to fix with a Dremel only made it worse...files and sandpaper and slow steady progress is what fixed it...and it was perfect in the end except for my new gray hair and lack of sleep for a week. Lesson learned...FILES AND SANDPAPER ONLY. if I have a lot of material to remove, like this one at the top of the tang and the rear of the trigger guard, I will use 60 grit. I don't like rasps because it takes a lot of effort to get the deeper scratches out. I like to work, then hit with 100 grit to quickly even out, and slide my hand along the area to check the feel. I don't like 1/2 hour of sanding out rasp scratches just to check the feel. Files and paper may take longer, but for me patience pays off. So that's my rant for the night. Back to the work...

I used a file and 60 grit on a block or on my thumb for curved surfaces, to level out most of the tang, down to the top of my pencil mark, and similarly for the rear trigger guard. For the latter, this effectively moved back the pistol grip, and made it more vertical. This was on purpose to help achieve the trigger position I like...tip of index finger touching the forward side edge of the trigger guard.

First up...I'm fitting this stock to MY hand...namely my left hand. No one else's. The vintage rules and military morals forces me to stick with the classic profile...but we can put in some minor, subtle ergonomics. I like the start of the comb to be steep enough that my thumb has a clean, easy to repeat, reference point. I like a small palm swell that tells me "yep...this feels perfect right here..." every time I slide my hand up into position. I like the tip of my trigger finger to touch the front side edge of the trigger guard. On a 1903, given how my finger is shaped, that gives me a perfect, repeatable trigger position. So, put the bottom metal in, and slide your trigger hand up the stock into your desired position.
Attachment 116777
I trace out the areas I want to use as a reference. The rear of my palm, the pad of my thumb that makes contact in front of the comb, and the bottom pad of my index finger. This marks the "OD" the material to be removed. I then use a micrometer to measure those parts of my hand, palm pad, thumb width, bottom index pad, and use that as an estimate for the ID. Trace it all on the stock in pencil, then make symmetric markings on the other side.
Attachment 116778
I worked these areas with a half-round file, pausing round out and even out the edges with sandpaper and remove most of the tool marks quickly, 100 grit works quick for me and the files I used. I check often by sliding my hand up the stock into position.
1) I started with the front of the comb as my main reference point. I made it a bit more vertical, and a bit deeper, providing the start for a narrower "waist", blending up to the tang which in the end will flush with the metal, or maybe wood a fingernail proud at most.
2) I next cut in the front of my palm swell, rounding to the underside of the wrist and into the pistol grip area. This completes profile for the wrist. I don't use a micrometer, and I don't have a set "size" for the wrist...I just go till it feels right for me. The minelli stocks start of sooooo fat that there is no curve in the wrist area and it's "slab sided" back through the palm to the but. Because of this and that my hands are big enough, I have zero worries of removing too much wood in the wrist.
3) I then work the rear of the palm swell. It starts at the base of the pistol grip and, following my palm, arcs up and gets lightly blended with the front of the comb. In order to keep the classic military lines, the swell is not pronounced here. Looking at the stock from the side you likely wouldn't notice it. A SUBTLE arcing blend up to the comb give the tactile feel normally achieved with flutes, but without being visually noticable. Subtle is the key...everything is enough to notice the comfort when the shooter slides a hand into position, but not very visually noticable.

Here is the left side (trigger hand for me) roughed in with the edges of the curves blended in. Slight palm swell in position
Attachment 116779

5) Now I repeat the same process on the right side. Normally, perfect symmetry would be the goal. BUT...while I shoot predominately left handed because I'm left eye dominant, I am right handed...and the USMC taught me to shoot weapons that required right handed shooting and I got pretty good at it. Ever notice how holding something in the same way in one hand then the other still feels different? Symmetry gives me the rough idea, but I fit the right side to my right the same way I did the left. Rough in with a file, sand to even out the edges and curves, slide your hand into position to check the feel, and repeat until you like it. Perfect symmetry be damned. It'll be close enough to even that no one would notice it unless they pulled out a micrometer.
Attachment 116780

6) I have been finish sanding all along with 100 grit so far for the whole stock. So now I blend in all the areas around the wrist and pistol grip and remove all tool marks. It helps find areas you miss by wiping your dust off with mineral spirits, or lacquer thinner. I circle areas with a pencil that need more work. Leave the butt alone.

7) my final finish will be 150 grit. Starting at rear. I sand the comb, then the underside, then the sides, and work my way forward. I always do the top and bottom surfaces, then the sides to make sure I don't miss anything. Wipe, circle any tool marks or areas that need a few more swipes. Don't worry about the handgaurd alignment...your not shaping just knocking the grain back a bit. Stay away from the butt, and be careful of the edges at the bands.
Attachment 116781
most of the original stain is still on the surface around the butt.