The increasingly widespread use of the metallic additive manufacturing process enables the design of components with ``complex'' geometry, such as structures featuring waveguides, which may exhibit complex dispersion due to their inhomogeneous characteristics. There is a high demand to characterize the geometric defects associate with phenomena occurring during the manufacturing of the sample, such as the thickness variation. Through numerical and experimental investigations, we explore the propagation of ultrasonic waves in additively manufactured elastic plates, with a specific emphasis on accurately reconstructing its shape using two methods based on propagative Lamb modes induced by laser. Our results demonstrate strong agreement between the calculated profiles and the reference.