Not seen before
Translate suggests Catalan
so yes, civil war refugee stamps of the Municipality of SARRAL
Sarral is a municipality and small town in the comarca of Conca de Barberŕ in the province of Tarragona in Catalonia, Spain. It includes the settlements of Sarral and Montbrió de la Marca. Montbrió was originally a separate municipality, but was incorporated into Sarral in 1972.
I'll check my Civil War Catalogue, it may take some time
this Catalogue is a doorstep, weighs about 2 Kilograms (or seems to be)