An Unusual Scott 662

This is easy ... well, at least it is for me now ... but, once I came to understand what had happened, I always found the situation amusing. While perusing my duplicates today, I stumbled across an old friend.
There's something wrong with the Scott 662 shown below.

Perf rate is wrong.

You are, of course, correct. What I found amusing is that, while someone reperfed the right side (presumably to make the stamp seem more presentable), they managed to use the same gauge as the top & bottom rather than the left side (11 vs. 10.5). Or perhaps they used the flat plate gauge rather than the rotary gauge by mistake. In any case, if you were going to reperf a stamp, one would think that you would double-check to get the correct gauge.

People tend to use the tools at hand, and many collectors would not notice.