The dynamic Coarse Integral Holography (CIH) display demonstrated previously can scan the low space bandwidth product (SBP) holographic images delivered by a high bandwidth spatial light modulator (SLM) to form a hologram array for angular tiling of the 3D images for a large field-of-view but only a modest size despite the utilization of the full bandwidth of the SLM in use. In this paper, we propose a scalable approach using seamless spatial tiling of the full bandwidth images generated by two high bandwidth SLMs using a resonant scanner and a high performance galvanometric scanner for a scalable CIH display capable of achieving twice of the final image size and doubled horizontal field-of-view (FOV). A proof-of-concept system is demonstrated with integrated full-parallax holographic 3D images. The proposed method has the potential to tile images generated by more than two SLMs for scalable large size and wide FOV holographic displays.