One thing, Willie, is that most single-action shooters drop their little finger under the butt of the grip. Gives much better control.
Here are some "grip-pics" that I just took with my cellphone. Recognize, though, that I'm holding the pistols out at arms-length AND at nearly a right-angle to the way they should be pointing.
First the Uberti New Model Army:
Second, the Pietta New Model Army. Note the difference in how much my thumb is having to "reach" to grip the hammer:
Finally, and for comparison, here's my grip on an Uberti 1861 Colt Navy. As you compare the images, you can see that my grip on the Navy is much more "compact" due to the smaller grip. (Unfortunately the focus is a little off...)
Hope these help!