Alright, I’ll take your collective silence to mean that you’re too busy digging through parts books in an effort to solve my problem to respond, but since I’m incredibly impatient:
Are these what I need? I can’t find any pics of them in use, but some comments seem to indicate that it’s intended use is for the housings and not the cables.
The ones you referenced here are used (primarily on road bikes) where the cable housing enters the frame on the downtube. It often rubs against the headtube, wearing off the paint. You pop those on, or alternatively put a clear sticker at the point protecting the paint.