The Findagrave profile I mentioned above for Stanley Lee Morton, b. 29 Jan 1906 Philadelphia County, Pennsylvania, USA had links to his parents, and that person's parents for a couple of generations.
So, based on this very possibly fictitious and tenuous connection (the name, year of death, and possible connection to PA), here is a possible lineage based on Stanley Lee Morton b. 29 January, 1906.
HIS father was also named Stanley Lee Morton, born May 25, 1877 (according to Findagrave). That Stanley's father (possibly your cousin Stanley Lee's grandfather) was Thomas J. Morton, born in 1833. Thomas J. can be found on the 1880 US census for Philadelphia, PA along with his wife and family: https://www.familysearch.org/ark:/61903/3:1:33SQ-GYBV-9YD?i=12&cc=1417683 .
Thos J Morton Male 46 Married White Engineer Self, born in Massachusetts, father born in Massachusetts, mother born in Massachusetts,
Catherine A Morton Female 44 Married White Keeping House Wife born in Pennsylvania, Father born in Germany, mother born in Pennsylvania,
The census also lists these children in the family: William J. Morton, age 10; Washington Morton, age 6; and Stanley L Morton age 3.
So, if any of the above speculation is correct, your great-grandparents were born in Massachusetts. I'll stop there, since I have no way of knowing whether any of this even applies to your search.
Once again, good luck!