They had fewer boundaries and limitations than they would have had elsewhere, yet even the outlaws possessed an underlying sense of honor and their own peculiar brand of integrity. By necessity women played a strong role in the development of the west. I can't explain the fascination of the west in a paragraph, but the above covers some of the reasons I like to write in this era. But I probably wouldn't. I'm told I do too.
Collaborations tend to blend the voices.
In my opinion the result lacks the unique energy of the authors original voice and vision. You've written successful books before and you can do it again. Sometimes this even works.