We don't have that as a single item, but we do have 2 parts that could be combined to make a pin with a round gluing surface.
Page 85 has a 25mm round disk for gluing:
http://www.rings-things.com/Catalog_Pages/085.htm
It could be glued to one of the pin backs on page 10:
http://www.rings-things.com/Catalog_Pages/010.htm
#38-302, the .75" pin back, would work well. #38-303, the 1" pin back, would be just a teensy bit too long.
--Polly