Okay, I'm a day late- yesterday the 28th was actually Jack Kirby's birthday! I thought I'd include a scan from the Collected Jack Kirby Collector v. 7- an excellent over-sized magazine which publishes hard-to-find copies of Jack Kirby pencils. Above is a rejected cover for Thor #144. The caption argues that the cover was rejected because Vince Colletta was too lazy to ink it! Well, I won't beat up on Vinnie, considering the page rate at the time was probably 15-20 bucks per.
It does make me wonder what the phone call to Jack was like when they decided to dump it- "Yeah, the cover was good, I guess- I was just hoping for something with a little more pizazz- I dunno..."