I apologize for the jpg artifacts, but here's an extract of the relevant page, with the contrast and brightness adjusted for readability...
Darlington and Sugar Creek Township are very close geographically, so it seems pretty likely that this is the right Allen family.
The next image I found on FamilySearch Pilot was from the 1850 census in Franklin Township, Montgomery County, Indiana. I'm guessing that this census was taken before John married Sarah, as he is listed as a 28-year-old laborer who was born in Ohio living in the household of Sarah Deford (age 50, born in Kentucky) on 24 July 1850.
So, the questions that remain include:
- How did John know Sarah Deford and Jane Clouser, the other members of the 1850 household?
- Who were John's parents and where did they come from?
- Did John have any siblings?
- What was Sarah's maiden name and who were her parents?
- What happened to Ira, Asa and Charlie?