With respect to the "book binoculars" LeBeau holds right up to his face immediately after the opening credits, the spine reads, "National Conference of Social Work, Detroit, 1933." The National Conference on Social Work (NCSW) was an American organization that began in 1874 and hosted annual conferences as forums for discussing various social issues and solutions to them by an array of individuals involved in social welfare and reform such as Jane Addams. The organization changed its name several times, including in 1917 when it was re-christened the NCSW, which lasted until 1956 and thus is historically correct for the purposes of Hogan's Heroes (1965). By 1985, the organization was defunct.
The title is based on the self-help book 'How to Win Friends and Influence People' by Dale Carnegie and published in 1936.
This is an instance where an actor plays of character of the same name. It is not 'Karl Swenson as himself', but rather 'Karl Swenson as Karl Swenson'. The actor is not playing himself, he is portraying a character that has the same name as himself.
UPDATE: Slight correction: The actor Karl Swenson is credited as playing a character named Karl Svenson, with a "v" replacing the "w" in the surname, presumably to make this "Swedish scientist" sound more Swedish. Or, in this case, more Svedish.
Additional Update: Note that, in German, the 'W' makes the English 'V' sound, so, in Germany, the name 'Swenson' would be pronounced 'Svenson'.
UPDATE: Slight correction: The actor Karl Swenson is credited as playing a character named Karl Svenson, with a "v" replacing the "w" in the surname, presumably to make this "Swedish scientist" sound more Swedish. Or, in this case, more Svedish.
Additional Update: Note that, in German, the 'W' makes the English 'V' sound, so, in Germany, the name 'Swenson' would be pronounced 'Svenson'.