This is a scan of a birth record book for dad (Frank II) probably filled out by Muriel (Gaga).  It lists all his brothers and sisters with birth places and day of birth.  Still working on getting all the years right.  It includes George Thomas (mickey) who was born 4 years after dad according to mom (Gloria), so that must have been updated later.  The siblings are:

Lois Mary born in Russell (Ontario?), May 5
Olive Annie born in Russell, May 9
Barbara Grey(?) born in Mandan (North Dakota near Bismark), Aug 7
Marian Ethel born in Bismark, ND, May 25
George Thomas born in White Bear Lake, MN, Feb 10

I have found further information on Barbara which has a middle initial of M so not sure about the Grey that was written down.