Ivory scales? have questions

Just picked up a new razor from theBay, hasn't arrived yet, but I thought I'd get a couple questions out there

Based on the pics, description and age I'm pretty sure they're Ivory, though I don't own any so I'm no expert

Question is, there's a crack near the wedge pin, seller says it's stable.....but is there anything I can do to assure it doesn't loosen up or spread?

And, just for curiosity sake, did I do alright price-wise at $75? I'm not upset at the price, but was surprised I was the only bid lol

early 1790-1810 straight razor clark & osborn stub tail natural handle not bone!
based on some info I found, the description is a little off on the age. From what I hear they were only Clark & Osborn from 1822-1832