... but as we know, even simple Research Questions can sometimes be more complicated than you'd think.
Here's what I did in each case...
So... what IS this creature?
The pin is about 1 inch long (2.5 cm) and the "collar" clearly snaps into a groove around the center. (It's also a bit more circular than my sketch, but you get the idea.)
What IS this gizmo? How do you search for something like this?
[ piano covers for sale ]
and found a number of sites that sell piano covers (including ones that are designed and cut for exactly THIS piano, a Kimball baby grand). Reading through the descriptions I found they're made of either Mackintosh fabric (a kind of rubberized fabric that's made of multiple layers--read the fascinating backstory of how this fabric was invented) OR a kind of multi-layer fabric with a vinyl layer. All of the covers come in either flat (i.e., one layer) or quilted (multiple layers of fabric, stitched in a protective quilted style).
1. Sometimes, just sometimes, using another search engine actually improves your search! In this case, Yandex' search-by-image gave us exactly the right result. Big lesson here--if one doesn't work, try another one (Bing, Baidu, and Yandex all have good search-by-image functions).
2. Often a near-miss can give you clues about how to improve your search. In this case, I learned the word "clevis" from a SERP that wasn't great. But when I search for that term, all my results were excellent. Learn from your near-misses!
3. Consider the value of searching for a product that covers what you're seeking. If you're searching for something that someone might sell (like a piano cover), you can search for it and learn a lot by reading the descriptions.