The 3M people responded to my email inquiry, and confirmed that the maroon #7414NA pad is the same material as the maroon #7447 pad. However, according to them, the grit for both of these pads is actually 280-320, and not 320-400 as listed in the FAQ section here. Their response was:
"Thank you for your inquiry. We appreciate hearing from you. The materials in question are the same however the grit is 280 - 320. Your interest in and use of 3M products is appreciated."
If some maroon pads actually say 400 on them, someone at 3M is confused. Either way, they are close enough for me for my needs.
Edited on 8/20/2008 3:00 PM