I'd probably go for any 'traditional' type pattern but with 30's repros? A grandmother's flower garden would definitely fall into the 'vintage' category - at least in my mind - but do you have the time or desire to do something that involved for this project? I'm about useless with links for you but maybe google some quilt museums and see if you can look at quilts from the 30's/40's era for some inspiration? Good luck.
ETA: I would think 'homespun' might be their understanding of 'old fashioned' so maybe stay away from those type fabrics. Just a thought.