Your information seems quite at odds with that given at this link:
https://thebulletin.org/premium/2024-03/russian-nuclear-weapons-2024/
Estimates are that Russia has over 4300 strategic warheads, and something like 2000 more tactical warheads available. Russian nuclear forces have been undergoing modernization, and Russia has working designs for hypersonic glide vehicles among other options.
I guess we’ll see how well their warheads work if they resume testing…I hope not on Ukrainian soil.
Another article on modernization:
https://www.defensenews.com/global/europe/2024/02/01/russian-leaders-have-high-hopes-for-new-nukes-this-year-again/
To your point, despite a fair amount of searching I couldn’t find an article on current warhead (pit) manufacture in Russia. Do you have a link perchance?