...on closer examination, maybe the entire housing goes through the internal routing, but it's hard to tell for sure, one way or the other. How about it Alex? Does the housing stop at the frame-fitting, or does it go all the way through to the brake?
I say it's a cable-stop, which would make the most sense, but I could well be wrong. it works that way on a similar vintage tandem i have, but i wish it didn't, because that's a lot of friction on the cable that would be eliminated if the full housing snaked through to the rear. As it is, I replaced the bare cable with telflon coated cable, and the rear-brake works, barely.. I question if it ever worked very well. Too much friction. Only teflon cable saved my sanity on that one.