Shop Manager Jerry Armogon & Artist Belmont Freeman review modernist birdcage. Gratz Industries has produced prototypes models and "mock-ups" for sculptors , industrial designers, architects, furniture and interior designers for over 75 years. We welcome the opportunity to work with our clients' concept development and offer the option of prototyping when drawings and renderings are not satisfactory in evaluating the scope of a given design, or when a client needs to present a model for further development or approval.