Curb stop lid

My water curb stop lid is getting very old and tatty. It's seized up to.

It does come off without any problem.

Anyone know where I can get a new one?

Call your water works company,they fix them here for free.
It is usually property of w/w co.
Unless it is privately owned.

There are probably about a thousand different makes and models, but your water company would have the one used by them in your area. however, it IS supposed to "have a problem coming off" so kids cannot decide to fill it with dirt and rocks.