An amusing aside—
Of course, Gil Kane stopped being the regular GREEN LANTERN artist in 1970, with issue # 75 being his last regular story. However, he would return to the character—his best known and loved—again and again over the decades for covers, single issues, special stories, guest-appearances, sketches, trading cards, pin-ups, etc.
And, pretty much every time he did, he drew the round V1 ring, despite the fact that the design had stopped being the default in 1976, and would not again become the standard until 1989-1994, and then again in 2004. Now, this was all good and fine for sketches and other such side work, but, in order to try and maintain some semblance of continuity in the actual comics, other artists clearly came in to revise the art and update the ring design.
For example, Kane’s original art for the opening splash page of GREEN LANTERN # 156 shows the V1…
…but the final page shows the V2.
Kane’s preliminary sketch for the cover of GREEN LANTERN # 166 shows the V1…
…but the final art shows the V2.
The original cover art for # 170 appears to have had Wite-Out applied over the rings of both Hal Jordan and the alien Green Lantern below him, and the V3 design crudely drawn over them.
TALES OF THE GREEN LANTERN CORPS Annual # 1 features its title characters inconsistently wearing V1s or V2, depending on the panel, with evidence of redrawing. This panel clearly features what appears to be a Kane V1 signet ring quickly reworked into a V2, with the added sidebars and central hole.
The original art for ACTION COMICS WEEKLY # 603 features what appears to be a paste-up, with another artist drawing the continuity-accurate V2 and cutting/pasting it over the V1.
Regardless of continuity or editorial tweaks to his art, Kane nearly always drew the V1. Although, frustratingly, unless it was a close-up panel, he tended to draw it VERY abstractly. Literally as just a circle on a character’s finger: