You already posted the most famous, Richard Wolf. Check his channel Democracy at Work. You can also check audiobooks of classic books like Marx's Capital or Lenin's Imperialism, but there is not much else that I know, I honestly recommend to just read books if you wanna learn about it. I wish the USSR had lasted a decade or two more, this way maybe Progress or some other editorial would have published CDs with marxist audiobooks idk.
I'll post a couple of pdfs that I have about political economy, you might find them interesting if you wanna learn about that topic. Also, I recommend that sooner or later you read some works on dialectical materialism, since they are the foundation of marxist political economy, otherwise your understanding of marxian economics will be superficial at best. Despite what some say, diamat is not a meme.