Besides upside down??
Hard to tell from just a picture.
I think we would need a little (or a lot) more detail.
Are you sure it's lead??
Is it hard metal.
How big is it.
what does it weigh.
That sort of stuff.
Even with that it may still be hard to tell without a metal spectrometer.
You can do a specific gravity test and maybe get an idea.
I think it maybe just an advertising paperweight from Eyre.
Or Tinners lead
Good luck.
Looks like the solder used to join the old cast iron sewer pipes. They'd melt a potful pack the pipe joint with oakum, then pour the solder to fill the joint with a ladle.
Have you tried googling the manufacturer or "Tandem Specialty Alloy"? Special alloy could be used for tinning wires in a solder pot setup too.
The Eyre Smelting Co made a wide variety of specialty alloys. I have found no specific reference to what you have, but previous speculation seems to be going in the right direction. Did you do any kind of Internet search prior to posting here?
Got it! Google up the companies name. They might have an online catalog. Look for solders. My buddy jogged my memory (not an easy job!) a lot of electronics companies order solder in ingots like these to use in solder pots. The pots were / are used to "tin" larger wires & cables. If you draw a blank there, check companies that manufacture wire harnesses & cables. Keep us updated with what you find!