The Pentagon issued its annual China as gathering military threat/peer competitor report (.pdf) last week. And, surprisingly, China is not in a vacuum-tube buying frenzy to revert back to 1950s or earlier military hardware. No, they're actually modernizing their military. Because that is exactly what nation state conventional militaries do.
Foreign governments have the same constituencies we do. Their people demand to be defended from potential foreign threats and their defense industries want to sell their products. So, you either buy new stuff, or go the Russian route and let your hardware rust. But China has lots of hard currency, so they buy new stuff.
What are they buying? The usual, things like better command-and-control, precision weapons, longer range missiles, some new subs, the usual panoply of weapons that would prevent the U.S. Navy from parking a few carriers off China's coastline and commencing a prolonged bombardment of their country. It's what the U.S. Navy calls "anti-access" capabilites. Or, it's what the Chinese call defense. It all depends on your perspective.