I found my great grandparents on my father’s mother’s side in the 1930 census – after a very prolonged search:
After searching for a few hours I found Martin and Bridget on the 1930 Census - note: though the search page says "8 matches in 4 items" - there was only one that with the Martin/Bridget combination (my great grandparents)
then I accessed the page and found the full 1930 census page 3b:
The 1930 census page where the Bowman ancestors were found - the thing that's interesting is Martin Bowman and his parents were all born in Massachusetts (I already knew that Bridget was born in Ireland, which is stated here on the census page)
I found this information during a short free period on footnote.com. I am convinced that there are other free sources of information that I should be able to access. Genealogy doesn’t have to cost an arm and a leg. That may be something I might focus on in my research.