Where to go next? I'm reading a book called The Gates of Europe, which concerns this eastern European area, but mostly Ukraine, Belarus and Russia (or Muscovy). Just going back 300 years fantastically increases the number of valid next countries or sovereignties. But, to make it easy, and increase the odds of getting it right, the Russian Empire - a.k.a., the Union of Soviet Socialist Republics. One ruble, 1979.
Yes, indeed. Western Sahara was a Spanish colony, and the Spaniards did not want to give it up! From Maroc to Algeria with this 1964 two-centimes coin.