The age and the craftsmanship add a lot to the value( as you probably know)
. So even if the weight seems light, it is still just a fraction of the value. At a typical jewler, I could see that going for much higher than you paid. And for pearl lovers, unique items like that are invaluable. SoI would go with Slraep's suggestion and replace thepearls if you want a closer to round. I am sure many of the companies who frequent this site could help you out. Although, I think it loooks lovely as it is. I think it was a great buy!