hello Zoe K...
i knew Jessamine well! i think she had a house in Islington for a while?
for almost 20 years I had a special bead shop in Portobello Road. We often saw each other; and i was also selling my necklaces designed with fabulous antique beads through some of the same craft galleries around the country. i wouldn't be surprised if some of those beads in your bunch were acquired in my shop.
I am still living in London. Maybe i can help with some of your queries about the beads? -after this lockdown is over, of course...
Stefany