Here is an interesting experiment for anyone willing to try it.
First of all, I have said many time how I make a Munsell Neutral.
1. Take Black plus white to the desired value.
2. Take Burnt Umber plus white to the same value.
3. Mix the Burnt Umber and white into the Black and white mixture until you get a dead Neutral.
Keep a bit of the Black and White mixture in reserve in case you add too much Burnt Umber and White. The amount of Burnt Umber needed will vary from value to value.
But there are many other ways to do it.
You can post them here.
No matter what palette of colors one uses, it is beneficial to know how to mix a dead neutral out of them. If you can't, then modeling realistically will be a lot more difficult and the palette will need to be adjusted.
Try it for the colors Beth listed.