Stone cladding - paint over or remove

chances are its concrete molded to look like stone, very popular in 70s and 80s, if you remove you will have no external leaf to your house and will need to be built in block and rendered, easy enough to paint

if its from 70s or 80s i'll bet its this stuff, cork stone we used called it in the trade

That's a very different situation to what OP described. Not impossible that there no outer leaf, but it wouldn't be typical.

Case in point. There's an original leaf behind that colourful mock stone.

Oap said cladding. If it forms the outer leaf it’s not cladding. He may be mistaken, but mock stone forming the outer leaf is rare imo.

In the photo you posted. It’s not the outer leaf.