In the 1960's, Tunberg discovered the works of Cliff Westerman and Joseph Cornell. Their assemblages were so powerful that he was captivated by the narrative quality of this art form. Assemblage art seemed to be the natural three-dimensional extension of surrealism. After graduating from USC, Tunberg worked for Ed Kienholz and they became friends. Westerman, Cornell, and Kienholz inspired Tunberg's love affair with assemblage, which lasted for over 30 years.

In 2010, after focusing on marquetry sculpture for 20 years, Tunberg returned to assemblage to explore contemporary ethics and values and our dramatic cultural evolution, integrating marquetry to augment the imagery's message.