A couple years ago, this subject came up at an ACA rally "gearhead" session. Albeit on a bit newer Alpine, the aforementioned adjustable brake cable is routed around a pulley before connecting to the spring assembly. The problem was that the position of the pulley was not correct so the geometry would not allow for the cable to be fully tightened--apparently, correct installation of the pulley is somewhat depend on how the factory technician was feeling that day.
As a side bar, if the brake was out of adjustment and allowed to drag, over time this would result in worn drive line brake shoes--so proper adjustment may no longer be possible.
2003 40' MDTS
Garden Ridge, Texas