As I’ve said in many of my listings and on my site I’ve been collecting these things for over forty years and all of this time I’ve worked as a museum’s conservator. This has allowed me to meet many wonderful and interesting people over the years. 
I’ve never missed an opportunity to talk about antique and vintage art equipment and sometimes theses lovely people have volunteered information like we’ve still got grandmothers old paint box in a cupboard somewhere! Invariably it leads me to getting aquatinted with these treasures. Very often it seems that there’s no one in a particular family that has much interest in such things and sometimes often these keepers of the treasures want such things to go somewhere where they’ll be appreciated. 
That’s how I’ve ended up with lots of bits and pieces and these brushes are no exception. 
In my drawers there were a few others of a similar date to these which I can be relatively sure of because of where they came from. 
These I’m sure as the aforementioned others date to the late 18th century. It’s usually tricky to date such things as there design and construction changed little over a long period but I can say with some certainty that these are quite early. As such they would be just perfect in a box of a similar date. 
There condition is generally very good and although it would be a great shame to use them they could be. 
All three are brushes are probably intended for covering larger areas although the finer one could be used for other purposes hence its handle. Whatever there intended use was they are very rare. 
Very often these thicker and softer brushes had no handle but of course it would have been a simple matter to insert one into the hollow quill from which they are made. 
I think that they are made from Squirrel though the finer one could be Camel. 
Lovely things and delightfully rare.