Definitely hard, 50s era anvil

https://reddthat.com/post/60927334

What are we looking at? Are you polishing the top face to be usable again?
Yep, just decking the top to make it smooth and flat. Had been forgotten in a barn for 30 years.

It’s looks like it’s in remarkably good condition for 30 years in a barn!

What comes next after machining the top?

Anvils last a long time even in the shittiest conditions. They’re blocks of iron or steel and it’s hard for rust to really penetrate deep
Also I’d already attacked it with a flap disk to get most of the surface rust off, it was pretty fuzzy when I started.
I flipped it over actually, try to get the bottom parallel but I gave up after a few passes, it would have taken more than I was willing to cut.