You're so kind for even entertaining my pursuits!! Some of the cabinets I'm seeing in WWII era adverts from Britain seem more like it, at least the straight metal legs part. My family is from the deep Appalachian woods in America and have been for at least four generations which is about from when i think the Singer was bought. It seems unlikely that a cabinet of that sort would have made it across the pond to my poor rural family. I know the cabinet and the machine don't necessarily have to come from the same year, so i might see how many boxes of family photos i can look through to see if i can glean any clues there as well.
My Grandma, the last owner of the machine who might recall it's history, is 93 yrs old and living in a nursing home with advanced dementia. It pains me that the knowledge is so near, yet so far away.