Costa Rican 10c Airmail Stamp, 1937 National Exposition Issue

This item is a postage stamp from Costa Rica, specifically an airmail issue commemorating the National Exposition of December 1937. The stamp features a central vignette depicting a prominent building, identified by the inscription 'BANCO NACIONAL DE COSTA RICA' as the National Bank of Costa Rica. Above the building, a stylized airplane is shown in flight, reinforcing the 'CORREO AÉREO' (Airmail) designation prominently displayed at the top left. The denomination '1C' (1 Centavo) is visible in octagonal frames in both the top-left and top-right corners. The main color of the stamp appears to be a deep indigo or blue-violet on a lighter, possibly white or off-white, paper background. The design is framed by a thin dark border, and the stamp itself is perforated along all four edges, indicating it was part of a sheet. The bottom border includes the inscription 'EXPOSICIÓN NACIONAL DICIEMBRE 1937', clearly dating the issue. Below this, in a smaller font, 'WATERLOW & SONS LIMITED LONDRES' is visible, identifying the printer. The visible perforations appear intact, and the overall condition seems good with no obvious major tears, creases, or significant discoloration, though the image quality makes it difficult to assess minor imperfections or gum condition. The style is typical of early to mid-20th-century philatelic design, emphasizing architectural and historical significance within a formal layout. The craftsmanship of the engraving by Waterlow & Sons, a renowned security printer, suggests a high level of detail and quality for its time.