chinese translation

Maybe . . .
pinyin: wú chǎn jiē jí wén huà dà gé mìng, literally "Proletarian Cultural Great Revolution"; often abbreviated to 文化大革命 wén huà dà gé mìng, literally "Great Cultural Revolution", or simply 文革 wén gé, literally "Cultural Revolution"

Agree!

I think the 文化大革命 or 文革 is ok.

Missing Chinese Characters
The missing Chinese characters are noted by ????? and ??. (Yes, I'm sure they're "O.K.") There are sites on the Internet where they come up as .jpg. Sorry, I don't have time to look for them.

The missing words are the same as you entered in your post. 文化大革命,can you see it?

I think the wú chǎn jiē jí wén huà dà gé mìng is often used in the formal historial artcles, it's just my advise.

Thanks