I owned an earlier vintage Moto Grand Jubilee (still my favorite bike ever) and it came with the same centerpull Weinmann brakes. I found them more than sufficient, even with 30+ lbs of touring gear in steep hill country. Whether or not you get new cables and housing make sure that the housing is properly sized. Even bike shop prepared bikes sometimes have housing that is looped too long, especially at the handlebars. That results in some of the lever movement and pressure going into the housing instead of the calipers. Also of course if you stay with the current cable/housing make sure it's well lubricated. Use oil, not grease.