It may have come in a box with plumbing supplies, but it sure looks like a spark plug removal tool. You use a bar or screwdriver through the holes in the tool to spin the plug in or out. Each end is sized to fit different spark plug sizes.
Picture 1 *seems* to have a square cross section and picture 2 clearly has a hexagonal cross section. Your language makes me think it is one device.
My geriatric memory (which is most certainly reliable!) makes me think of a hex tool that came with my '67 Karmann Ghia (fancy VW) for the lug bolts and the spark plugs. Really not too sure.
Have I misread picture 1? To quote Admiral James Stockdale, Who am I? Why am I here?"
Yah that's a tub handle/stem socket. I found a set long ago in my dads garage when going thru his stuff and thought they were the cheapest **** sockets I've ever seen n tossed them. He use to buy alot of cheap sets.
Had to buy a set last fall for our tub, kinda regret tossing them all these years later LOL My set cost $20 at Ace Hardware.
Could literally be from anything, cheap stamped socket included in various products that require assembly or removing bolts for maintenance, i have a pile of them that have come with chainsaws over the years, though they usually have a handle (with or without a screwdriver tip, making it a scrench) where those holes are
I was lucky to find a NOS set of those from Chicago Specialties Manufacturing Company. They were an older company making plumbing tools and supplies. Now out of business.