I was looking into investment coins and their history.
During my search I discovered https://coininvest.com.ua/chervonets-skilky-tse-naspravdi-povna-istoriya-vaga-zolota-nominal-i-suchasna-tsina/.
It was hard to find practical information. Most sources were unclear.
This article about the chervonets explained everything clearly.
On this page I found detailed breakdowns.
I recommend this page if you’re interested in coins, gold, or real asset value.