Paul Davidson gives a talk here on mercantilism from the perspective of the international payments system. There are also good, but brief, comments on the opposition of Keynes (1933) to the principle of comparative advantage (from 28.22-29.20).
This was part of a panel entitled “Is Mercantilism Doomed to Fail? China, Germany, and Japan and the Exhaustion of Debtor Countries,” held at the Institute for New Economic Thinking (INET) Paradigm Lost Conference in Berlin (April 13, 2012). The second video is the question and answer session.
Keynes, J. M. 1933. “National Self-Sufficiency,” Yale Review 22.4 (June): 755-769.