Mine came from eBay, and is the CT24LX06 one you mention. I can't think of anything outwardly visible that is different, unless they changed the brackets that the stereo and climate control bolt on to. The double Din install link in my signature might help to see if the pictures shed any light on differences.
for wiring diagrams, I uploaded these a while ago, but not sure if they'll match yours or not.
Mk2 Radio and Player.pdf
Mk2 Navigation.pdf
Mk2 Radio up to June 2000.pdf
Mk2 Radio from July 2000.pdf
Mk2 Nav up to June 2000.pdf
Mk2 Nav from July 2000.pdf