I have one of those -- and mine also shows a more subtle the vignetting that yours does. It's really a remarkable little camera. Until I get a baby Rollei or a Yashica-44, it's the best 127 film camera I have.

Mark, if you're going to get another 127 camera, don't aim low. Look for a Sawyer's Mark IV = Primo Jr. Much, much, nicer and better than the Yashica 44s and baby Rolleis.
Cheers,
Dan