I updated my question while you were responding.
There is a random wallpaper setting in WindowBlinds 7.42 under wallpapers option.
The "Random Wallpaper Changer" that opens when you click on "Random Wallpaper Settings" often becomes "not reponding" and crashes.
Also, as I said in my more descriptive update to my question, "(t)he WindowBlinds 7.42 version does not allow time settings of less than 1 hour, where DeskScapes 3 will change as fast as every 30 seconds - that's too often for me, but I have been using 5 minute changes for years."
I will reinstall DeskScapes 8 again, just to make sure that the user can actually randomly change wallpaper based on directory as DeskScapes 3 can, and as well as trying to get the WindowBlinds 7.42 changer to actually work. (It may not be working properly since I have DS3 running, but it still has the time setting problem, stated above.
The last time I installed DS8, I could find no way to control "Random" wallpaper - I do admit that I did not fully investigate the entire product.
Also, WindowBlinds 7.42 needs to be fixed so time increment changes allow for settings of less than 1 hour.