Thanks for all the suggestions! I will take them and begin my quest first thing next week. The pillow is a 2009 item but I don't know which season. I've seen some blogs touting this pillow and they're dated in August and September 2009. I don't know if I can find the SKU number. It's wiped off the C and B website except for a mention in their reviews section, but the SKU isn't listed. I do know it's called the Carmen pillow, and came in plum, teal and chartreuse.

Do you have a Habitat for Humanity ReStore nearby? Ours usually has a lot of old boxes of tile. Might be worth a shot.

I googled daltile salerno marrone chiaro (sl83) 18x18 tile and it seems like tile stores have it? Might have to pay for shipping, but might be worthwhile?

You didn't reference the model number of the range. I found that part number also associated with several cooktops. Is it #2 on this diagram? The discontinued P/N 3191817 that you reference is stated as biscuit color, not white. White is WP3180081 which is available. W10854242 is black. The are numerous online parts sources, my go-to is usually PartsDr. eBay is a source for new-old-stock discontinued items and used items ... depending on if any sellers are offering a particular item at a given moment, otherwise keep checking back there if you're willing to wait for it to come up.