mybutterflyiris,
Hey there,
one recommendation I might have for tweaking a scanned image is to try this 2 step process:
- Desaturate the image (Ctrl + Shift + U, or Image > Adjustments > Desaturate)
- Set the Levels to Auto (Ctrl + L > Click āAutoā, or Image > Adjustments > Levels > Click āAutoā)
This almost always helps my images. The desaturation bit is important ~ youāll get worse results if there is color information (for drawings), at least, so Iāve found.
You can also manually adjust the 3 sliders in the Levels window, the left slider (triangle) is for darks, the middle slider is for middtones, and the right slider for lights. Try experimenting with this and hopefully it will help. 
I like the bottom version quite a lot ~ in terms of the drawing itself, I mean. Do you think you will draw the rest of the figure as well? 
Cheers, 
~Rebeccak