I found another grab bag treasure. I ended up with a 16x16 stud clear(ish) base plate. A quick look at bricklink gave me a no items found message. I'd like to know which set(s) this piece can be found in as I have grand plans in mind.
Any of these three sets
Bricklink hint: just search for a size, like "16 x 16". "3x3 plate" is fun too.