"Two color typographic rotary press 'Goebel' model B.P.M. used by the Mint (Casa de la Moneda) to print postal stamps. It was acquired in 1935, even if installed in its printing shop (taller) since November 1930 in test mode (a titulo de ensayo)."
I had heard about some 35 years ago as I was studying the stamp printing history of the Leiden firm "Nederlandsche Rotogravure Maatschappij".
Leiden is my home town and the place where I was born....
In their archives I found several stamps/essays related to Argentina and Mexico a.o. The NRM was instrumental in promoting the new types of rotary presses the Goebel AG was producing! Mainly for photogravure and recess but as they were into to typography a lot earlier also typography rotaries...
However, as J. Merlo is stating in his book, the CdM did not buy a photogravure rotary in Darmstadt but a sheet-fed press from the German firm Mailänder in Stuttgart in 1938. Still they did buy a Goebel 4-colour reel-fed rotary press in 1968 with the options to have the perforations done in-line - that is a perforator affixed onto the press.
It is strange that the Goebel had been mainly used for definitives - not in multicolour [!] - and hardly ever for commemoratives. Most definitives of the Próceres y Riquezas set in photogravure had been printed on the old sheet-fed machine with the direction of printing and the direction of paper perpendicular to each other. Occasionally the 2 directions can be found parallel!
After 1968 the systematical use of the Goebel for definitives was responsible for the introduction of an alternative stamp size! A slightly longer oblong stamp size that can be found for several defintives of that period. And what was just described as a change of the size of the stamp design [!] which it was NOT! It had to do with the new Goebel reel-fed photogravure rotary press...
