The Hippocampus Press book H. P. Lovecraft: Letters to Elizabeth Toldridge & Anne Tillery Renshaw (annotated) appears to be shipping now. I mentioned it here last May, when it was set for shipping in August. But it was delayed. Now Wilum Pugmire has a print copy to show on camera, and the Hippocampus Press page for the book has it as available for order.
Above: cover of The Credential, an amateur magazine Lovecraft co-edited with Renshaw from early 1919.