Yes, that looks like them, Kay99.
TGB, a look on Scotland's People at the birth certificate of one of the children would verify that. Go for Oliver, as his is the most unusual name.
Three deaths of Pauls with mother's maiden surname Masson in the deaths indexes at SP. One is Alexander Paul, who died in Torphins in 1976 aged 77, so would be a perfect match for the two-year-old Alexander Paul in that census. Unfortunately you can't look at that death online as it's less than 50 years ago - you would have to order a copy to be sent to you, or wait until the Scotland's People Centre is open again and someone could look at it for you.
Also Elsie Paul, mother's maiden surname died in Dufftown in 1986, aged 92. Also too recent to view online.
If these are your family, it would suggest that the parents did not emigrate, and that the death in Illinois is someone entirely different. There is in fact a death of an Alexander Paul, aged 82, in Aberdeen in 1953. You can, and should, look at that certificate if you think he might be yours.
(Marion Paul or Farquhar, mother's maiden surname Masson, died in Elgin in 2007 aged 81. However this looks like a Marion Farquhar who married a Gregor Paul, so nothing to do with your Pauls.)