Due to the fact that I have some interest in Arnstad in my own family tree, I came over your need for help.
Your posting is about a year ago so you might have already found what you were looking for.
John Pedersen (Son of Peder) Arnstad born 29/12-1802
* 9/10-1826 to Ingeborg Pedersdtr (daughter of Peder) Myhr (She remarried because her first husband drowned in 1823.
They got four children:
Peder born 7/6-1827
Ellen born 28/9-1829
Ingeborg Anna born 24/12-1831
John born 24/8-1836.
The parents of John Pedersen Arnstad were:
Peder Johansen Arnstad baptised 18/3-1770, dead 1/2-1846.
* 17/6-1800 Ellen Johnsdtr Skjervold born 1780, dead 8/5-1832.
I enclose pictures of the Arnstad farm.
Hope this information was of some help to you.
Ole H. Sandvik