The close-ups help. From the main picture it looked like the tri-prong end is riveted on, which wouldn’t make much sense, but in the close-up picture it’s clear that the “rivets” are engraved digits. A part catalog number? A measurement of some sort?
What does the middle of the three prongs look like end-on? Does it have a socket in it? That piece definitely looks like it’s meant to mate onto something else.
Yeah, a part off of something.
This is what I was going to say.
A balance beam for weighing.
Let’s try this in GQ. Thread relocated from IMHO.
It is not some kind of hand tool. There is no handle and the spine is not strong. It is not built for leverage.
The hook indent on the top looks like it is where the end of a spring rests. The small end has a hole meant to receive a rod.
I am thinking lawn mower deck part.
Guess:
Farrier’s jig … one end to pry off old horseshoes … the other to hold a horseshoe in place whilst the farrier nails it on …
It looks similar to a transmission shifter arm.
looks like a lever off a locomotive or other heavy machine, one that engages and operates a gear or valve or something at a certain point in a cycle and moves freely during the rest of the cycle.
It looks like a multi-tool specific to a particular machine or vehicle. On the far left is an offset wrench, in the center is a gear or wheel rotating tool and on the far right is a spanner wrench.
It would help if the tool was flipped over and photographed.
it just occurred to me, its a driver arm. the hole near the hook is where it attaches and pivots. the end where the hook is looks, from the pic, to be forked as if it coupled with a rod or something (perhaps used to engage the mechanism before starting the cycle), the hook engages a belt/gear/valve/whatever to be advanced, the small hook like notch in the middle is where a control/return spring was attached and the three pronged end was engaged to an offset pin on a rotating driver wheel (held in place by the spring) and the whole thing works kinda like ratchet
I thought that at first but the more I look at it, based on the size, some sort of home-made tool for using on a wood burning/pot-belly stove. The right side with three prongs reminds me of the tools to lift the “lids” off the burners/covers and the left side would have been handy as hell moving wood around getting the right placement for an even burn and poking the coals on a re-light. That little hookish bit just right of center is a mystery but it could have been for hooking/turning a flue maybe.
I’m pretty sure ** GusNSpot** has it. It is a beam from a large balance.
Seconded. One end for prying off, the other end to hold the shoe in place twixt the ends and center tongue. There’s an ‘open end wrench’ at the end of the prying fixture that resembles a farrier’s wrench for holding a shoe while filing it.
Tripler
$10 bucks, or a load of hay says watchwolf49 and I are on it.
Looks like part of a scale to me, too.
It looks similar to some of the old refrigeration compressor service tools I have seen. I think it is used for removal of clutches, or blades, maybe pulleys.
It is a multi tool used for opening different types of 55 gallon and smaller drums. I am pretty sure. I knew I have seen it before.
You’re thinking of things like this, but I don’t think the scale is right.
The left end looks like a removal tool. For an oil seal for instance. The end would engage a shaft that goes through the seal. Then you could pry a bit in a spot and then rotate a bit. Working your way around with the end on the shaft keeping the tool lined up nicely. The other end ? Maybe to install the seal? The fork fits around a wider portion of the shaft. You tap the lug in the middle a bit while rotating around. Tapping the seal in a bit at a time.
I am more inspired by the left end. The right end speculation is a wilder guess.
I have no idea what it was, but it can become a yard sculpture. Adapt. 
Yeah, I’d say some sort of weighing arm - I’m thinking maybe part of the shutoff mechanism for sacks being filled with grain or meal - when the sack attains a specific weight, the thing swivels and pushes on a rod linkage fitted through the hole in the end, transmitting force to a gate valve or similar, shutting off the flow.