The European Society of International Law's organ, EJIL, published a thematic section on international legal history in its last issue:
Giovanni Mantilla, "Conforming Instrumentalists: Why the USA and the United Kingdom Joined the 1949 Geneva Conventions" (483-512)Prof. em. J. Weiler's introduction to this issue can be found here.
Narrelle Morris and Aden Knaap, "When Institutional Design Is Flawed: Problems of Cooperations at the United Nations War Crimes Commission, 1943-1948" (513-534)
Felix Lange, "Between Systematisation and Expertise for Foreign Policy: The Practice-Oriented Approach in Germany's International Legal Scholarship (1920-1980)" (535-557)
EJIL can be consulted with OUP online, or on iPad or iPhone (for ESIL members or subscribers).