Note that the index numbers are only technical numbers which have no persistence. After a new system generation is done, all of them are invalid. To generate a persistent link, use the name.Use the URL:
http://ww-person.com/cgi-bin/l3/LANG=germ/F=Ludwig@Otto@Wilhelm@Wolfgang/N=v.Unger
Ludwig Otto Wilhelm Wolfgang v.Unger
alternatively: /cgi-bin/llmult/LANG=germ/P=53123571