Here's the story: I was given an old Cannondale road frame, likely an '88 based on the serial number, but the paint was completely stripped and all the plastic bits were missing. Cdale frames of this era had snap-in brake cable guides, removable downtube shifter bosses, and an odd little bolt-on front derailler bracket.

Here's the question: Does anyone know a cheap source for these parts? The top-tube cable guides I could make do without, but the shifter bosses and front derailler tab are, well... necessary. Thanks in advance for the help! I cross-posted to bicycle mechanics, just in case.