Notes on diffeomorphism classes of the doubling Calabi-Yau threefolds

Previously we constructed Calabi-Yau threefolds by a differential-geometric gluing method using Fano threefolds with their smooth anticanonical K3 divisors [DY14]. In this article we further consider the diffeomorphic types of the resulting Calabi-Yau threefolds starting from different pairs of Fano threefolds of Picard number one.