This study explores the in-plane capacity and repair actions for unreinforced masonry (URM) perforated walls, by testing experimentally piers and spandrel assemblies, addressing both the original structural response and post-damage structural repairs. Initial experimental in-plane tests on full-scale masonry piers and spandrels, composed of solid fired clay brick and hydraulic lime mortar, focused on the significant role of spandrels under monotonic loading, simulating differential settlements. The results identified a sequential in-plane failure mechanism involving flexural and shear cracking in the spandrel, followed by shear cracking and rocking in one of the piers. The response was characterized by high ductility, nonlinear behavior with moderate hardening, and eventual flattening. In a subsequent phase, damaged URM piers and spandrels underwent repair using two techniques: high-performance lime-based grout and Fiber Reinforced Cementitious Matrix (FRCM) systems. Post-repair testing revealed that grouting alone restored the original shear capacity, with enhanced post-cracking stiffness and ductility. The combined grout and FRCM repair further increased shear capacity and displacement ductility by over 50% and 56%, respectively. Ambient Vibration Testing (AVT) confirmed the improved in-plane stiffness in both repair cases. The use of analytical models, accounting for the strength contribution of the FRCM, validated their use for assessing and designing repairs. The study underscores the efficacy of these repair techniques in restoring structural integrity of damaged URM structures and recommends further experimental validation of the proposed analytical models.