I have the same bike but circa 1990. I would say that you have a 1991 or 2, particularly given the era of Look pedals. It is in very good condition for that age of bike.

As for the comments bout frame cracking, perhaps on some but this is not a common problem that I have ever heard of.

I took yee old Cannondale out for a ride yesterday. It sits in the bike holder as my Merlin is THE ride. I was instantly reminded of how well the Cannondale climbs and sprints and also reminded of how it feels on the harsh stuff. Ouch! This is a great bike for smooth roads.