Guilloche Cloisonne Enamel Butterfly and Flower Pendant Tassel Necklace

I've been trying to find the name of the manufacturer and years that this popular Guilloche Cloisonne Enamel Butterfly and Flower Pendant Tassel Necklace, Bracelet, and Earrings were made. No luck "so far", but I'll keep at it of course. My mother was quite taken with the Guilloche Cloisonne "pillow" necklaces that have the design on both sides with a long, usually 5" tassel in the same color as the fabric neck "chain" - which also usually had a barrel, screw clasp.

I have "sort of" narrowed the purchase time frame down to late 1980's or early 1990's, but don't have any solid lead on the manufacturer at all.

I'd appreciate any suggestions on how to locate the manufacturer of this style of jewelry that was prominent in the 1990's - or any other period of time this style was somewhat prominent in stores.