Check this out:
http://www.albabici.com/nalini/fabrics/pads-info.htm
The Nalini 25 chamois pad is extremely simple; I have that in two Nalini team replica bibs. The PTN1 and PTN9 chamois are close to the 25 in simplicity.
Some mountain bike shorts liners and cycling liners have very simple flat chamois too. I actually don't like any of them because I'm fairly lightweight, they are like huge diapers on my body, and the few I have seem very low quality compared to my road bibs.