How to get this efect (for GIMP):
1. Get your base ready. If it is too dark, you might wanna get it a bit lighter, lets say using Curves somewhere around 104x177 (depends on how dark the picture is.
2. Now we are going to use Channel mixer with these settings:
Red: 140, 0, 0
Green: 0, 130, 0
Blue: 10, -20, 110
3. Make a new layer, fill it with #b0991a, set it to darken only, 30% opacity.
4. Make a new layer, fill it with #b01a1d, set it to overlay, 50% opacity.
5. Edit/Copy visible - Edit/Paste As/New layer. Go to Colors/Hue-Saturation and use these settings:
Master: 0, 0, 40
6. Open Channel mixer and input these settings:
Red: 110, 0, 10
Green: 0, 110, 10
Blue: 20, 0, 110
7. Channel mixer once again. This time use this:
Red: 130, -10, 10
Green: 0, 120, 0
Blue: 20, -20, 120
8. Now we are going to play with color balance. Colors/Color Balance:
Shadows: 0, 0, 0
Mid-tones: 20, 0, 30
Lights: 0, 0, -20
9. Make a new layer, fill it with #a17a5a, set it to multiply, 50% opacity.
10. Duplicate your base, bring it on top, set it to hard light, 50% opacity.
11. Edit/Copy visible - Edit/Paste as/New layer. Open Channel mixer and use these settings:
Red: 100, -20, 0
Green: 0, 100, 0
Blue: 0, 0, 100
12. That´s pretty much it, if you want you can add text in #968b52
If you feel like sharing I would be very glad to see your results :)