The Vintage Shoes of Mystery

I love it when a vintage find sparks a bit of mystery. Take, for example, these lovely dark navy suede shoes. I found them on a thrifting hunt several weeks ago in San Francisco and was immediately drawn to their beautiful shape and soft and supple leather. Truly a vintage gem I was thrilled to find.
The style is very classic 40s and, although the shoes are in amazingly good condition, on close inspection you can tell that they are pretty darn old. I listed them as 1940s in my shop but then, on a lark, googled the name inside of them, Silvia of Fiorentina.
It ends up Silvia Fiorentina (without the of) is a high fashion Italian shoe designer whose shoes currently sell for between 200 and 500 dollars at places like Nieman Marcus. I tried to find out when she started designing shoes (and when she dropped the "of" to better date them...) but all I could find was that she helped influence design in the 1960s. How long she has been designing shoes or if she was designing shoes when she still had the "of" was some information I simply couldn't find...
I'm still listing them as being from the 40s with a huge disclaimer. You can take a closer look here. I would love if someone could help solve the mystery though, so if you have the answers, please let me know. As a side note, I also love the shoes still have the name of the original owner, Aida Ducata. Hmm....If I google her, who knows what I'll find. ;)

Anyone else have some vintage mystery stories? I'd love to hear them.