Watch List notes:

(x) El Banco de Espana, a reverse proof for a proposed issue of 50 pesetas mounted on card, ND (1937), brown, pale green and value in dark blue, galleons at right centre, (Pick unlisted, Los Billetes del Banco de Espana 1979, p.318/319 for issue), printed by C.&C. BANCONOTE MILANO (ITALIA). The firm printed 25, 50, 100 and 1000 pesetas.

Estimate: £250 - £300