I haven't been following this thread closely, but there is a Moses Kinvig (and brother?) in Montana Death Records:
Last Name, First Name Middle : Se x : Age : Death Date : Year : Index Number
KINVIG, MOSES : M : 75 : 30 Apr 1935 : LC 1214 :
KINVIG, JOHN J : M : 75 : 31 May 1939 : Ana 3153 :

Sue