If you post pictures you will find a lot of people on here are familiar with patterns in the 30's and 40's. I think you will be able to confirm your suspicions even if you cannot get an exact year. Your other option is to find a museum close to you that has a textile department. Usually there is no charge for them to take a look at an item. In fact at this time you might be able to do it all by email and pictures. The 1930's and 40's are not that long ago when it comes to having information available.