My newest, a 400A

There's a tiny speck on the bottom-right 10. It shows more in the enlarged scan than it does on the actual stamp. And the top-right corner perf is pulled, but I can live with those issues. And I'm pleased with the centering.
Below is the back of the stamp which made me do a double-take...

At first, I thought the image was showing through, but on second look, apparently the "image" on the back was picked up from the face of another sheet. The odd looking 'dot' in the bottom-right corner is from the scanner glass, not on the stamp.
KirkS