The info for his parents was unknown to the informant who was not a relative. It lists his cause of death as an apparent drowning. The date he was buried was July 17, my guess is that they found the body a short time before. More than likely there would have been an article in the newspaper about finding his body. His obituary and funeral notice may have been in the paper as well. If a relative came to town to attend the funeral or to claim the body it too may have been in the paper. His occupation was a tailor.
According to the 1900 census Frank P. Kneipp and Dora of Nebraska were married 11 years. Their marriage record may have info on the parents. If you haven't already I suggest getting Frank's death certificate and obituary. The obit may have info on siblings if it doesn't list parents as well. The 1930 census shows Francis Kneip 66 was born in PA and his parents in Bavaria. Frank is also in Nebraska in the 1920, 1910 and 1900 censuses.
The following may or may not be the right Frank and Harry but looks worth looking into. Harry was apparently a loner.Kneipp is found spelled many ways in these records.
Harry Knepp 70, tailor, is in the 1930 census living in Marion, Ohio. It lists him as born in Ohio. Harry Kniepp 59, born in PA, tailor, living in Pickaway, OH in 1920. I couldn't find Harry in the 1910 or 1900 census. The 1880 census lists a Henry Kneiff (or Kneipp) 19 living in Junction City, KS and working as a tailor, born in PA. The 1880 census also lists a Frank Kneip 16 living in Lancaster, PA.
The 1870 census may be the key to the whole puzzle.
Lancaster, Lancaster Co., PA:
Adam Knipe 43, born in Bavaria Margt 43(?), born in Bavaria Eliza 17, born in Bavaria Mary 15, born in PA Peter 13 Henry 10 Frantz 6
Adam appears in the 1880, 1900, and 1910 census living in Lancaster County. In the 1880 Frantz and Henry are gone. I believe Adam remarried and his second wife's name was also Margaret. The census indicates Adam immigrated either 1852 or 1858. He was born March 1827. Peter seems to have stayed in Lancaster County and may have died 1920-1930.
Some of these records you can look at for free at labs.familysearch.org and Ancestry.com. For those you cannot see for free I suggest checking with your local libraries to see if they have Ancestry or Heritage Quest.
If you feel this could be the right family I suggest contacting the Lancaster County Historical Society, Lancaster Family History Center and perhaps the Manheim Historical Society. If Adam had an estate file it may be helpful in proving the connections. It would be on file at the Lancaster County Register of Wills. Adams obituary would probably list surviving children. Peter's obit might list his surviving siblings which might include a Frank of Nebraska.
Once you determine Adam to be the father of your Harry and Frank you may want to get Adam's death certificate. He was a naturalized citizen. He probably filed for naturalization at the Lancaster County Prothonotary Office.