Well, as a matter of fact, I have 3 such items to post. These are my favorite and best finds to date (though I always love a wheatie, and I only have one silver merc).
First is a contentious button, because can't really get a handle on the actual manufacture date. There seems to be a lot of disagreement as to when these were actually issued. But nonetheless, I think it is a cool button. Scovill
Second, a Cavalry insignia. Again, not sure of the date, but almost sure it is around 1900.
Third, is my new gem, and currently my Avatar. Found this in the sandy depths below the great fire of 1906. There was traces of foundation wall below the fire level which indicated to me that there might have been a cellar or basement level which was common, so this button might have been lost down below, prior to the Earthquake). It is and Infantry Officers Button, Waterbury Button Co.