Old Butler sink - advice on how to clean/what to use

[Unhurried]

I am now the owner of a very large Butler sink which was formerly housed in an artist studio. The sink is covered in paint, mainly water-based I think. It's probably about 50 years old with years and years of grime. I'm thinking it will ultimately need to be re-glazed/re-enamelled but need to get it cleaned up first. Any advice on how to do this and what to use would be appreciated.

Use Cif on a sponge scourer. I cleaned up two Belfast sinks from our old kitchen - the outsides where they'd been built in to units were dirty and the top edges where the worktops had been glued on. I used bleach to clean up where there were cracks in the glaze. Then I sold them.

Thank you wow, will give it a go.