The Metatron is an angel who appears in Jewish, Christian and Islamic lore. He doesn't appear in the Torah or the Bible but shows up in the Talmud, in the Kabbalah and the book of Enoch. In that book the title character, mentioned in Genesis 4 and 5 as a man who "walked with God and was not", becomes an angel and a high ranking one, sometimes sitting in for God. He appears in Good Omens and is mistaken for the fictional character Megatron.
The scene in The Resurrectionist with the jukebox shows someone trying to play The Proclaimers: Letter from America (1987). Douglas Mackinnon also directed the music video for the song.
David Tennant (Crowley) and Derek Jacobi (The Metatron) starred together in Doctor Who, with Derek being the Master before he regenerated into John Simm.
Following the brief reference to Iain Banks' novel, "The Crow Road." in Chapter 2: The Clue featuring the minisode A Companion to Owls (2023), this episode shows the book cover fully on screen twice for extended periods of time. No part of "The Crow Road" bears any clear link to the events of this season or the last, other than the similar fates of the book's protagonist's grandmother and the fate of Agnes Nutter in season one.
At the pub The ressurectionnist at 26'12 they are frames of "Pressburger beer" on the wall, that's a reference to the Powel/Pressburger movie "A matter of life and death" (with the first Stairway to heaven).