How old battleships could become convoy force multipliers

What could the Royal Navy do with its First World War pre-dreadnought fleet if those ships appeared during a war beginning in 1949?

Refit them for convoy escort, where their guns could deter or delay surface raiders and release modern battleships for other theaters.

If First World War-era pre-dreadnoughts arrived in serviceable condition during a 1949 war, the Royal Navy could refit them as long-range convoy escorts. They would need better underwater protection and would not solve antisubmarine defense, but their heavy guns could deter a raider or delay it long enough for a convoy to scatter and modern forces to intervene. By taking those escort assignments, the old ships could free R-class battleships and other capital ships for the Mediterranean or Far East.