Very thin hand-painted lines are drawn around his blue irises as already discovered.
1963-64 2nd version Japan-made #750 brunette painted hair Kens with original body/arms
expected order of this eye: 1.eye(white, stencil/spray), 2.iris(blue, stencil/spray), 3.eye liner(dark brown, hand-painted), 4.thin lines around the under eye(brown, hand-painted), 5.pupil(black, hand-painted, stamp), 6. very thin lines around iris(brown, hand-painted).
1963-64 2nd version Japan-made #750 painted hair Kens with turquoise eyes
the thin hand-painted lines are also drawn around his blue irises, but thicker and darker. the colour is almost black.
1963-64 3rd version #750/0750 blonde painted hair Ken
this Ken is my oldest boxed Ken, he and I have been together almost 30 years!, but I had been wondering if this #0750 Ken was 1964 or 1965? because he had no clue, he was missing his original plastic pack with booklet and sandals.
Now I think he is 1964 #0750 because his pupils are drawn with hand-painted/stamp. he should have a 1963 booklet or 1964 booklet!