Theo's theater credits include:
- Swan Song
- Land of Fame
In 1957 it was announced that Theo's Guiding Light character, Papa Bauer, would be celebrating his 65th birthday. In response, fans of the show sent Theo over 40,000 letters, cards, telegrams, and gifts. He admits that he "burst into tears" when he saw them.
Theo was portrayed by Emmy winning actor Justin Deas, on the January 25, 2007 episode of Guiding Light. The "Inside the Light" episode told the story of how the show got its start in radio and moved to television, complete with the actors/actresses of today playing the stars of yesteryear.
Before coming to the United States, Theo was a leading actor at the State Theater in Vienna, Austria.
Just prior to the outbreak of World War II, Theo was able to escape Italy on the very last Italian ship which was headed to the United States.
As a soldier in the Austrian Army during World War I, Theo was captured by the Russian Army and then spent time as a prisoner-of-war in Siberia.