I attended HWA's Worldwide Church of God from 1971 to 1995, when I left because of the "apostasy from within".
Notice, that HWA did NOT understand Chapters 4 or 5 of Revelation... referring to them merely as "Prelude - Setting" on page 9.
It was not given to him to understand these.
We can understand these NOW - seeing Ch 4 depicting Holyday 2, and Ch 5 depicting Holyday 3.