Originally Posted by Retro Grouch
You haven't done this, have you? The cable stop that you're talking about faces the wrong way.
No, I've not used that particular part. However, from the description, it looks like it would be possible to flip it around so it faces forward from the seatpost, thus allowing it to serve the purpose of a top-tube mounted cable stop with the housing headed towards the rear brake.
As far as I can tell, the part is designed to attach to the seatpost clamp bolt and face backwards, thus providing a front-facing cable stop behind the seat clamp. But I see no reason it couldn't be flipped around to provide a rear-facing cable stop in front of the seat clamp.
For $1, seems like it might be worth a shot.