stnmikita,
Welcome to the forum. I have copied and pasted your 4 points to answer them.
1. It's an M30 variant of the C96 and from what I can gather that was the lowest mass-production numbers of the main types of C96s.
Yes, M30 or M1930, a little over 100,000 of the variation made, if memory serves.
2. Manufactured somewhere in the 1930's, probably closer to the beginning of the run of these or toward the middle?
1930-1940, Yes, yours has features of early and late production and that puts it somewhere in the middle.
3. I believe the stock and grips to be original to the gun based on the color match of the blue-fired hardware on both and the info I can gather on the style/characteristics of the stock and grips.
Everything looks correct and original.
4. Personally, I'm really leaning toward this being original finish and condition.
The M30s have a hot salt blue finish, It does look like older Colt finishes. All earlier C96s have a cold rust blue finish. From what I can see everything looks correct and original. Congratulations! you did very well in an area that can be a mine field.
Regards,