The Franquist rebellion would have failed in less than two weeks if not for the German support.
His troops were in Africa, waiting for transportation into mainland, but the navy remained faithful to the legal government. Therefore, if the Nazis hadn`t helped him to cross the Strait of Gibraltar, he wouldn`t have been able even to start his war.
You ask why in Asturias most of Franquist symbols have not dissapeared. I have a theory for that. First, things are not the same all over Asturias. Oviedo is, let`s say, quite a conservative city, to say the least. Second, I wonder who might be interested in changing those symbols...since power here, is seized mainly by the same people as in the days of dictatorship, or their straight descendants. The change from Franquism into, say, "democracy", was such a soft one, that eventually it became clear that the current regime regarded the former as a legal one. That is why, for instance, the Policia Armada (the Spanish version of the Gestapo) was scattered, but its officers earned their retirement as any honest worker, while the veterans from the Republican army didn`t get a dime, and the partisans who fought in the mountains after 1939 remained in their mass graves, and recorded in the files of local police stations, as "bandits".
In the walls of the city hall of Oviedo there is a engraved stone with the titles of the city, those praises that the kings of Castile and Leon endowed us across the centuries, due to the faith and feats of our ancestors: "Muy noble, muy leal, benemérita, invicta y heroica ciudad de Oviedo". It was Serrano Suner, Franco`s brother-in-law, who called Oviedo "Invicta y Heroica", that is, "Undefeated and heroical". Since Suner had no authority at all to endow Oviedo those names, the Socialists in the town hall suggested erasing those two words from the stone. The answer of the mayor it was SUING them for insulting the "good name" of the city.