Lost am I with the 20th C US databases

But could this help with Dorothy Green Gatto perhaps:
Dorothy A Gatto
Birth Date: 11 Apr 1919 [11 Apr 1921]
Address: New Bern Twrs 2m, New Bern, NC, 28560
[PO Box 2593, Granite Shls, TX, 78654-2678 (1995)]
[100 Windwood Dr Apt 16, Kingsland, TX, 78639-9702 (1995)]
source: U.S. Public Records Index, Volume 1
Which then fits with one of the Dorothy's you found on SSDI:
Name: Dorothy A. Gatto
SSN:
Last Residence: 78639 Kingsland, Llano, Texas
Born: 11 Apr 1919
Died: 2 Aug 2006
State (Year) SSN issued: Pennsylvania (Before 1951
It's the New Bern reference on the first set of details that caught my eye, connecting back to James Jnr's obit.
Monica