I think I know a part of the story. COMERIMSA was a company based in MAdrid with offices in Sagasta Street and also in Fuencarral 101 st.
Comerimsa meaning was COMERcial de Intercambios Mundiales Sociedad Anonima. They had 5 or 6 divisions. Division number 5 was musical instruments. The object of COMERIMSA was trade with former East countries (DDR, Poland, Czeck...) exchanging products.
In Spain it was not allow to import or to export products from or to these countries. So COMERIMSA put in conection companies from Spain with the Goverments of the DDR, Poland, etc, etc in order ro "exchange" products.
I'm very sorry because my English is not good enought. The guitar could be a guitar made in DDR or in CZECK before 1992. The sticker with COMERIMSA name inside is because at the end of COMERIMSA'S days, COMERIMSA sold directly some products to music shops.
If you like to know more please contact me at jmgm2008@gmail.com

regards from madrid