Would Civil War-style monitors have helped Spain in 1898?

How would an American commander react if half a dozen Spanish ships modeled on Civil War monitors appeared off Cuba?

The American commander would welcome the encounter because those designs were about thirty years out of date.

The scenario gives Spain six ships modeled on American Civil War monitors. By 1898, those designs were about thirty years out of date. An American commander would welcome the encounter because the additional ships would be weak opponents.