For the Freightliners the FLD is the square nosed class 8. FLD132 is the "classic", 132 inches from front axle to back of sleeper - front axle not set back, the front tires are right up against the bumper. FLD120 has the front axle set back so 120 inches from front axle center to back of sleeper. FLC is the Century Class and they are FLC120, sloping hood and more rounded grill. Maybe the Columbia fits into this one too. In all these the cab interior and sleeper are essentially the same and they can come with a raised roof or a mid roof that is about like the truck cab height.
My Volvo experience goes back to the first rounded looking ones and the 610 had a 61 inch sleeper and it height was the same as the truck's day cab. The 660 had a 66 inch sleeper with a raised roof. The 770 had a 77 inch raised roof sleeper and it had windows at the driver's door level that the others didn't have. The newer Volvos have numbers like 780 and 880, etc. which is a take off on the earlier set.
On truckpaper you can comper photos for the different listings and see the differences.
Hope this helps.
medent, El Paso