If David arrived in 1904, there was no wife listed with him. I find it interesting that if David was naturalized in 1924, why was Mollie not at the same time? I believe the wife would have been naturalized with the husband if they were married at the time.
Have you found a marriage for David & Mollie, likely in New York?
When Beile (Bella) and Jacob (Jacow) arrived in 1911, they were in the guardianship of Leiber Schlecter. All gave their birthplace as Pesozuaje, Wolyn gub (gubernia), Russia. In this timeframe, this area was part of western Russia.http://en.wikipedia.org/wiki/Volhynia