Birdbath

…Not sure where to post this…please feel free to move it wherever!

I rescued this old thing out of the brambles behind a relative’s house we recently sold. It seems pretty darn old…unfortunately it doesn’t hold water anymore so I’m going to have to try to seal the bowl if I want to put it into use. The cement/concrete is pretty pitted porous and I’m unsure what to use. There’s also small pebbles cast into the base or the bowl.
Any thoughts on age and/or tips on how to seal this poor old thing?
Thank You!