You can see an AK630 where Kashtan used to be. It's not a great weapon. You can only engage one target at a time and thus is easily saturated. The RAM copy is a much better weapon (assuming it is close to the performance of the US/German weapon) faster and much longer ranged and one launcher can engage 21 targets simultaneously. Having the guns separate from the missile launcher allows missiles and guns to engage different targets simultaneously.
The hull and steam plant used on the Sovremmenys are pretty much unchanged since the early 1960s and are based on the old Soviet Projekt P58 Grozny Class RKRs, the first of which was commissioned in 1963. The same basic hull and machinery were repeated in the Projekt 1134 Berkut and Projekt 1134A Berkut A class BKPs. Zhandov in then Lenningrad built all of these and recycled the hull and machinery one more time for the Sovremmenys. It is ancient by naval standards. The Berkut B class were gas turbine and built in Nikolayev on the Black Sea, same place their predecessors the Projekt 61 Kashin Class, the first warships powered by gas turbines, were built.