They remind me of my grandmother's pearls which I inherited back in the late 70s. At the time, I was thrilled with them. But in the last few years as I've met all the fine people on this forum and bought better quality pearls, I realized that Nana's pearls were not high quality. The clasp was still gorgeous, so I had PP match some new pearls to the clasp. I still have Nana's pearls in a little bag in my jewelry box. But I wear the new strand with the clasp and think of Nana when I wear them.
Your grandmother's pearls look like they could use a nice bath and a restringing with smaller, tighter knots. The clasp is very nice. The pearls may freshen up nicely. You may find the ivory color goes with some of your clothing better than the drop dead gorgeous gem quality pearls. Or you may decide you just want to keep them and not wear them.