[pmcjones]

Try these:

https://softwarepreservation.computerhistory.org/LISP/lisp15...

https://softwarepreservation.computerhistory.org/LISP/lisp15...

https://softwarepreservation.computerhistory.org/LISP/lisp15...

(The third one includes the source code to PDP-1 Lisp.)

[ozymandiax]

Wow! How did I manage to miss this treasure trove! Thank you.