John,
Your Grandmothers bike was built in 1942, sometime after the government's restrictions on bicycle manufacturing was implemented.
@Miq started a thread here on these war time Schwinns in 2019 and loads of information has surfaced since then. Take a moment to look it over, and a current list of these bikes is recorded on page 88.
@Miq doesn't have yours on the list yet.
Here's the thread.
Please help us gather some more info on wartime Schwinn New Worlds (or other lightweights). We know many of you have these unique bikes and they all have an interesting story to tell. We are already starting to get an idea of what serial number New Worlds have the transition from brazing to...
thecabe.com