Offerdahl family: Samson, Synneve, & children

I'm still learning my way around this site, so hope that it's OK to start a new topic with the family name in the title to make searching easier. This family was earlier discussed under the heading "Help with finding info," and was started about a year ago. My main interest in this family is the youngest child of Samson and Synneve, Robert J. Here is what I have gathered about him. Born in Hennepin County, MN on 14 February 1900. Family address at that time was 2419 8th Street, per 1900 census. (Google Maps shows that as now being a busy intersection; I think there are cloverleafs involved, but it's been awhile since I looked.) WWI Selective Service Registration, dated 12 September 1918, lists him as tall, with blue eyes, and medium build. Address was given as 5025 Xerxes Ave, South Minneapolis. (Google Maps shows this as still a residential neighborhood.) The Chicago, Milwaukee, and Saint Paul Railway Company was given as his employer. The 'next of kin' type of info listed just Synneve. Samson was still alive at the time, so not sure why just Robert's mother was listed. My mother's birth certificate, dated 29 September 1929, lists his age as 29, race as white, birth state as Minnesota, and my mother's status as "legitimate." She carried his surname until her marriage. The address given then was 1218 N. Superior Street, Antigo, WI. (I need to go back and look for that address on the maps; I believe I could not find it previously.) Robert's occupation was given as 'Salesman." (I had my memory confused when I posted on the previous topic page that he had been listed as a house painter.) Address on the 1930 census is given as 315 5th, Wausau. (Most likely a still extant residential neighborhood, though there are 3 versions of this address, modified by N., S., and street or avenue. One is the address of a house built in 1900. Robert's wife Eleanor had family in Wausau at the time.) Then, he disappears, until 1 small item I found, prior to his death as registered with Social Security. (SSN = 479-20-7706) In the Daily Reporter, Spencer IA, dated Tuesday 23 March 1965, under hospital admissions and discharges for local hospitals, Robert Offerdahl, of Hartley, IA, had been discharged from Hartley Community Hospital the prior Monday, presumably 22 March. (Again, didn't look at my notes before posting previously, where I wrote that he had been admitted.) Death is given as in December, 1966. There is a gravestone for just him in the Dickens Cemetary in Clay County IA. The picture available on Find A Grave shows just his name taking up the whole face of the stone, but the marker is nice enough that it seems as if someone had enough involvement to provide it; or, I suppose he could have made prior arrangements. The only other thing I have in my notes is a notation of "carpenter," which I believe is from reading a classified listing in an Iowa paper, though that is all I wrote. I am still pretty haphazard in my info gathering. Need to realize that even though I am the essential "end of the line" for this family line, someone somewhere might be able to use it.