My original tumblr post was here. This image is the cover for a comics series called Magnus, Robot Fighter which first appeared in 1963. Here is the cover with original context from Comics.org:
The image was originally posted on Tumblr by TOMORROW & BEYOND and comes to us via Fifi~ Feeling is First.
The artist did a great job on the cover art. Every issue was worth framing. The closing credit art for the Supermarionation series Captain Scarlet was very similar.
I always found the premise of this series sort of odd (yeah, I should speak), but I certainly agree with you about the art.