Well as of recent history they have been calling themselves the Kuomintang and neglected the Zhong Guo part to distance themselves from the PRC. However pre-1990 it was everywhere.
So yes, the ‘Chinese Nationalist Party’ or ‘Nationalist Party/Kuomintang’ are both good. Neither is ‘wrong’.
Even the “Taiwanese” military badges still have a silhouette of China (not Taiwan) on them.