From the bibliography of Martin Wycoff’s , “United States Military Buttons of the Land Services 1787-1902″, we find a referenced source of Officers and GAR buttons for sale through the 1902 Sears Roebuck catalogue.
A 1969 reprint , shows plated brass buttons, of the General staff type, for sale for .19 cents / doz. coat size and .13 cent/doz. vest size.
One can see them in use for school marching bands , veterans uniforms , and general or personal wear. Sears probably bought out vast lots of the now discontinued staff type buttons and sold them on the civilian market.
19 cents per dozen? Does not say the size.. Full (22 mm), Sack Coat (19 mm) or Cuff (13 mm).
Could be of mixed quality… Some of my CW buttons had blue cloth on the back.. like they were cut off worn out clothing and the uniform tossed into the trash…. Funny, most Frock Coats were kept by the owners while Sack Coats were worns and work clothing until they fell apart. I use my Private’s sack coat from 1988 (it is now 2023) to change oil, gardening.. have two CW original buttons on it… still useful. Yes, I’m a Reenactor since 1988 and still do it now (but numbers are greatly down since the peak in 1999).