unusual necklace set

I picked up another batch of estate sale finds.....this stunning set caught my eye! However once i returned home and had some time to inspect...well all of this jewelry must've been packed away for quite some time..lots of patina, so there's that questions of cleaning. I have read sooooo many different methods for costume jewelry it's confusing. Please offer me some advice. Then there's the wonderment of this set. There's def alot going on..especially looking at the earrings...slot of elements and I have never seen a back like this....thus far no indication of markings. The beads are some sort of plastic, see the seams? But they are knotted perfectly in between each and have an unusual swirl/vein of color. I would really appreciate some input! thanks!!! BTW what style would you consider these?