Mythlore: A Journal of J.R.R. Tolkien, C.S. Lewis, Charles Williams, and Mythopoeic Literature has a two-issue rolling wall, meaning that you can’t download the full-text for the last couple of issues. But, as time goes by, the articles gradually become free and public. You can bypass this by accessing Mythlore at the Free Online Library, where the latest couple of issues are available and public.
This means that while their new article “”Love of Knowledge is a Kind of Madness”: Competing Platonisms in the Universes of C.S. Lewis and H.P. Lovecraft” appears to be locked down until April 2019, it’s actually free here. The same issue also has “”Letting Sleeping Abnormalities Lie”: Lovecraft and the Futility of Divination”, and again it’s free here.