Years ago I salvaged an old upright piano for the ebony of the black keys and hopefully the ivory of the white keys. As it turned out, the white keys were an early celluloid of some sort, but the black keys were good ebony (bridges and nuts). I couldn't bear to throw the rest away, so I removed the iron frame, strings and soundboard and mounted it all in a 4X2 frame on the front wall of our house as a sort of "doorbell."
It's still there today and it still provides a rather novel way to announce guests. I measured the boards (photo below). The numerous main soundboards are ~8mm with some of the boards near the tuning bar going as thick as ~20mm.
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