Tim,
On the Sharp 10K using DVI input, in order to "imitate" the action of the (unavailable) brightness control:
Set the Gamma to "Custom 1" or "Custom 2." Then increase the R Offset, G Offset and B Offset by equal amounts. This increases the lower (black level) "anchor" of the gamma curve, which is what the Brightness control does.
The gamma Gain settings, used in unison, act like the Contrast control by setting the upper (white level) "anchor" of the gamma curve.
The gamma Gamma settings manipulate the "shape" of the gamma curve by altering the ratio of input signal to output light level. I'd leave those alone unless you know what you're trying to adjust or improve. In your case, increasing these somewhat may give you back the equivalent of the "Black detail" preset that you like.
If you're using DVI from your DVD player, you can use the Video Essentials or AVIA disks to help you get all of this just right. If, however, you're using DVI to bring in HD television signals (like I am), you've just got to eyeball it unless you find a channel that broadcasts test signals in the wee hours of the night.
-H.