Yes, that's a nice old period hilt that should go well on the sword. Is the
kakatua partly damaged? Even if it is, I don't think it detracts much from the hilt overall--it looks like it has seen some action, just as the blade does, so it's in keeping with the ensemble. Look forward to seeing the final product.
Before committing to a scabbard overhaul, you might want to see how the replaced hilt looks with the current one. This is a gnarly old sword, and a fancy scabbard might look out of place and not suit the character of its
gin.