Østen Syversen and Mari Pedersdatter

I am attempting to find more information about my ancestors Østen Syversen and his wife Mari Pedersdatter. They are mentioned at: http://www.bredebygden.com/Garder/Sandbu/gamleplassen.html as the parents of my ancestor Marit Østensdatter. I think I have their marriage record Vågå 1739 - 1810 page 103 2nd column # 6. I think I have Marit's birth. Same book page 47, 2nd column, 2nd from bottom. I did a census search (1801) and found two Østens both too young. I found a Mari, I think living with her son Peder, age 66. She would have been a 17 year old bride in 1752. Possible but I did not think likely. I could not find a birth record for Peder. I did find the death of a more age appropriate Mari Pedersdatter. Same book page 200 4th column # 21, she was 86 years old. Is there any indication this is my Mari Pedersdatter? I have not been able to find the death record for any Østen Syversen Any suggestions would be appreciated. Marlon Henvit Reno, Nevada USA