I bought myself a CE-2B yesterday and wonder if there are two knob-versions of it? If you look here http://www.bossarea.com/loadpage.asp?file=boxes/ce2b.xml you see knobs just like the ones on DM-3. Mine and the one pictured in the Boss-book have standard knobs, the grey-top ones found on many pedals. Boss-area, is it you own CE-2B that is pictured? As I understand it, the skirts on the DM-3-type is removable so there is a possibility that the skirts on mine has been removed.
Mine is MIT with a green label. The Boss-book states that these skirt-knobs was only used on DM-3, that´s why I went “nuts” about the picture on Bossarea.com.
The CE-2B picture is taken from a Boss advertisement that ran in Guitar Player around 1986-1987. Both versions exist, my own pedal has the normal knobs but now then you will see the ones with DM-3 knobs on Ebay.
Here's one on a Japanese site: www008.upp.so-net.ne.jp/ hashi/page061.html
As far as I know there aren't any other pedals than the DM-3 and the CE-2B that uses these knobs.