This is a very interesting and intriguingly mysterious spy case. I think it is very doubtful that this mysterious unidentified person will ever be named or identified.
One of the intriguing details that I happen to notice was that it didn’t say which German marks currency were found in the luggage at the railway station depository box.
Back in 1970 during the cold war era in Europe, Germany was separated into two different nations, East Germany and West Germany. Both nations had their own German marks currency. East Germany was a Soviet bloc nation back then.
Another intriguing detail is the black notebook with numbers and letters code that was also found in the luggage.
I suspect that the black notebook could either be deciphered messages or it was a one time pad used to decipher coded messages that were transmitted by numbers stations on the short wave radio band.
Here are two articles that explain what the numbers stations were all about during the cold war era:
http://www.dxing.com/numbers.htm
http://en.m.wikipedia.org/wiki/Numbers_station
And here is an article published last year explaining why numbers stations are still in use years after the end of the cold war.
http://www.bbc.com/news/magazine-24910397