Lisp from the early 60s used already images. It went from there to Smalltalk.
I believe you, but, do you have some reference? I would assume this came after Lisp 1.5, right?
http://bitsavers.org/pdf/mit/rle_lisp/LISP_I_Programmers_Man...
Page 66f: SET card writes a memory image to a tape and TST card reads a memory image from tape.
Lisp from the early 60s used already images. It went from there to Smalltalk.