In a previous post, I speculated on Kim Jong Il’s whereabouts in the late 1950s. Here at last is the original document (in the “unofficial translation,” followed by Kim Il Song’s original) which prompted that speculation. This also answers reader Ernst’s original question about the date: it was indeed 1956 in the first case, and the 1960 correspondence was about a delegation to Leipzig which would not include Kim Il Sung. Error corrected!
Thanks also to Pacific Lutheran University student Matthew Anderson for his assistance in Berlin. Those are some burly archives indeed.
Adam Cathcart 
Is there any English translation?
Good question; I’m working on some other stuff right now but will attempt to have one out there as soon as possible! I posted this the moment I received it and am thus already a bit behind in my own translation queue.