Thrawn, I am retired Canadian airforce and worked on the CF18 for 10 years. As far as I know...when I got out the only difference was the false canopy painted on the bottom. (and yes it was somewhat effective). They were "A" models (and still are).
They have in recent years gone through some avionics and weapons systems updates but are essentially still A models. Also 10 dual aircraft were originally purchased and are B models. The only difference between these 2 models was the addition of a back seat complete with all the toys and a slightly smaller #1 fuel cell (to allow room/weight for the extra seat).
I actually have about 20 hours inb the back seat. They fly beautifully, although it was real hard on the body. After my first ride I actually got out and kissed the tarmac lol. It sure gave me a new perspective on the abilities of the people who fly thse things for a living..I respect each and everyone of them.
Any way hope this clears things up for you.
cheers
RTR CO 421TFS