Moosic, those cut sandstone objects are pretty much un-dateable unless you know for sure of the person that made them. Probably the best you could claim was pre-1930 ish. Now chimney stones can be dated if they are "still in place" in the structure they were made for and you know when said structure was built.
For instance, the old Weston State Hospital, in Weston, WV, which was originally known as the
Trans-Allegheny Lunatic Asylum of Western Virginia, is or was the largest “cut sandstone building in the US” which was built pre Civil War.
As far as value they are "novelty items" so, ....whatever you can get for them.
Iffen you "make up" a cute story about them like "George Washington's horse drank here"
..... they will likely bring more money because the buyer will have "something to brag about".
Cheers