North Korea isn’t the only country that has used the chollima images on their postage stamps. Some of North Korea’s allies have used the image too. For example, from an image we have seen before on the Korea Stamps Society’s webpage is a East Germany pair with a semi-postal stamp of 20 +5 pf value on the left, with label in the middle, that has a chollima on the regular postage stamp 20 pf value on the right.

In 1960, North Korea’s best ally, the People’s Republic of China (PRC) issued a pair of stamps, each of the 8 fen value, Scott 525-526 commemorating the friendship between North Korea and the PRC. One of the stamps, Scott 526 shows features the image of the chollima.
Might want to fix an error on the captions. “CORREOS” just means postage in Spanish. Cuban currency is a peso divided into cents. “85 correous value” is kind of a nonsense phrase.
Thanks, Ian. Done. Bob