My guess is it was drawn by the designer but inspired by Milton Glaser's Baby Teeth font:
I couldn't find a font with this letter "S" (or "R"
) either.
Suggested font: Baby Teeth
Edited on Apr 10, 2021 at 14:05 by fmontpetit
I spoke to Brandon Rike, creative director for the album:
"Mix of Tenebras and Monarch."
Shoutout to cassie2006 for the clue to the old Monarch version.

Posted here many times but never really identified.
Since the logo is from 1972, my guess is it's a distorted version of Eurostile.
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