Check with a Cannondale dealer for their proprietary rear brake cable guides (on a CAAD3 frame they're plastic and snap into place on the top tube) and shifter bosses (the left and right bosses both screw onto a hollow tube that passes through the down tube). You can get away without a bottom bracket cable guide, but those are pretty easy to find.

Hope the hipster idiot didn't pry off the rear derailleur cable stop riveted on the right chain stay.