Reading carefully solves many interpretation issues. This affidavit was not filed on 29 January 1887, but if I look at the date in haste I may conclude that this was the date of the document.
The 1887 date was the pension act under which the widow was applying. Eliza Jane’s affidavit was actually made in 1892–five years later. Correct dates matter as information is given as of the date of the affidavit. That was especially true in this case as the affiant indicated that her late husband would have been 97 years old when the affidavit was made.
I easily could have gotten the year of birth five years had I used 1887 as the year of the document.