A few nice photo letters images I found:
letters from spanish anarchists
Image by margaretkilljoy
Five letters by Francisco Ferrer Guardia and two letters by Soledad Villafranca to F. Kupka. 1909-1910 and n.d. photo 2 of 18
letters from spanish anarchists
Image by margaretkilljoy
Five letters by Francisco Ferrer Guardia and two letters by Soledad Villafranca to F. Kupka. 1909-1910 and n.d. photo 3 of 18
letters from spanish anarchists
Image by margaretkilljoy
Five letters by Francisco Ferrer Guardia and two letters by Soledad Villafranca to F. Kupka. 1909-1910 and n.d. photo 9 of 18