I made three different versions. The only thing I didn't realize is the right side picture window doesn't scroll down It's not a big deal; it just means you can't see all of the right side (unless you turn off the picture window).
INSTRUCTIONS: Unzip these files and place them in your bkground folder. Start your MAMEUI/32 program and select Options>Background Image to choose your background.
PS: In the screenshot above you can see the custom folders/icons I did in the folder window. I'm still working on them. I will try to post those in another thread when I'm done if anybody wants them