Nowadays it's easy to find better quality pearls, so I'm wondering if it wouldn't be better to disassemble the necklace and sell the gold findings (tubes, round ball beads, clasp) either for their gold value (scrap gold), or possibly even sell the findings themselves to beaders for repurposing.
There are lots of people who like to make their own jewelry and who might prefer to buy your pre-owned findings at a reduced rate than to pay for new findings. But I think if you do that, you should get a scrap quote first (or several quotes, as different gold buyers may offer different amounts.) Go with whatever option gives you the best price. JMO.