Even from these pics I think I can determine that the grip is real ivory.
The whole dagger looks right as rain!
Patination, damastblade, all looks ok.
It is a shame to disassamble such a dagger! 1. you have to care especially for the right way in assambling it, 2. the fragile ivory grip might be seriously harmed and 3 the pommel might get an incorrect seat.
Imo never disassmble such a gem.
Regards,

wotan, gd.c-b#105

"Never look for sqare eggs" as a late owner of an original FHH-dagger used to say.