I think this is a old kohler but not sure the piece is 4 3/16 long and 3/8 back threads flange to end
here is a link to the pictures
http://www.kodakgallery.com/Slideshow.jsp?&mode=fromsite&collid=909289062106&conn_speed=1
here is a link to the pictures
http://www.kodakgallery.com/Slideshow.jsp?&mode=fromsite&collid=909289062106&conn_speed=1