Three Sets of Vintage Costume Jewelry in Original Box

I recently came into possession of several intriguing jewelry sets that have a rather complex history. The pieces were part of my grandparents' estate, which had been retained by my late uncle.

Background:
In 1999, my grandparents passed away, triggering a family dispute among their four sons, including my father. Ultimately, my father relinquished his claims to the estate. Fast forward to recently, my uncle, who had inherited everything, passed away and bequeathed the bulk of the estate to my father. Interestingly, the home had remained virtually untouched since 1999, preserving all of my grandparents' belongings.

The Mystery:
With no surviving relatives to shed light on these items and my father having limited knowledge based on childhood memories, I find myself in a bit of a provenance predicament. Although my grandmother had a history of selling Amway products from the early '60s to the '80s, these pieces don't seem to align with anything Amway-related that I could find.

Packaging:
All items come in an original box made of black plastic designed to mimic leather. The box has a gold-colored plastic trim and is lined with velveteen. The inside of the lid is padded, and there are specific slots for each piece, confirming that the sets are complete.

Set #1:
Features clip-on gold-colored sunflower earrings and a matching brooch adorned with opaline rhinestones and faux pearls. Earrings are stamped "REG. 269," and the brooch is stamped "REG. 267."

Set #2:
Comprises clip-on silver-colored earrings and a matching necklace, both encrusted with rhinestones. Earrings are stamped "REG. 572," and the necklace is stamped "REG. 456."

Set #3:
Includes clip-on silver-colored earrings, a matching brooch, and a necklace embellished with rhinestones and plastic black "stones." The brooch can be clipped to the necklace for added flair. Interestingly, none of the pieces in this set have any form of stamping or registration number.

I would be immensely grateful for any insights or guidance on identifying these sets. Does anyone have any information on what the registration numbers might mean or any clues that could help me uncover their origins?

Thank you for your time and expertise.