Ila "eye luh" (and Ilah) was a slightly popular name, probably around when your ggma was born. I think it's probably based on
Lila from
Delilah and
Ella, which were also used around then, and just fit in well with other popular names -
Irene,
Ida,
Iva. I know an
Ila who would be pushing 100 about now (not sure if she still survives).
Lou was fashionable too - along with
Louise,
Luella etc. Luila is probably just an invention based on combining those sounds. I like it! Although the pronunciation isn't intuitive, anymore.
- mirfak