In the 1920´s or now, irrespective of whether monetary base is mostly, partly or not at all made up of gold, GDP is always the flow of total production and income out of which Total Debt is serviced. So, comparing Total Debt to GDP across periods is always fair.
China’s Debt to GDP Compared to World Economies
Source: Beijing American Chamber of Commerce Presentation: by Yukon Huang. Dr Huang has held positions at the U.S. Treasury and various universities in the United States. He was the World Bank’s country director for China (1997–2004) and for Russia and the former Soviet Union Republics of Central Asia (1992– 1997). Before that, he served as lead economist for Asia and chief for Country Assistance Strategies.