Scripted download (curl) was refused by a Cloudflare "Just a moment..." challenge page (no CAPTCHA was shown in Chrome). In Chrome the PDF opened in the viewer (17 pages) but get_page_text returned no text; saving it would need the viewer's download dialog, which was avoided. Not downloaded.
Title page read from a screenshot: "Richard Chace Tolman 1881-1948. A Biographical Memoir by John G. Kirkwood and Oliver R. Wulf..." with a third name partly legible (ending "...EPSTEIN"; probably Paul S. Epstein [memory, medium]). Copyright 1952, National Academy of Sciences. Springer and Wikipedia snippets cite it as Biographical Memoirs NAS 27: 139-153.
Bearing on the claims
Priority 4 (historical record): the memoir by Caltech colleagues is the standard account of how Tolman came to relativity (MIT, Lewis, Berkeley 1912-1916) and normally carries a full bibliography, which would list every Tolman relativity paper. Next run: ask the owner to save the PDF, or read it page by page from screenshots.