This stamp is the interesting one which started my thinking.
It is partially shifted - as a result of a 'slip print' - this is quite noticable in the Upper Left.
It shows what appears to be doubling in the O of Postage, and of course it has the very important horizontal line at the Upper Right and the key marks in the Lower Left.
For the details of my thinking about the marks in the Lower Left, please visit this page.
There are several re-entries which show very similar re-entering in the O of Postage, but of interest is a red brown 2nd Ottawa copy - dated March 9, 1897 - which shows both the doubling in the O and the horizontal line in the UR. Sadly, the bottom margin is too small to show any indication of the LL marks of 6R5.1. To see that stamp, click here.