Brandon, As far as the reliability of the earlier units, the biggest problem was the cable track motor guide, being made out of aluminum, the cable guide channels that are on both sides of motor gear that drives the cables, (handcrank units are the same) would wear away, then the drive motor starts slipping on the cables, the motor or hand crank gear starts getting worn down, then the panel is rendered useless, and the emergency crank handle won't work because it operates the gear drive,....my cure for this was to machine a new cable guide block out of steel, then double CASE harden the alloy, so that it had about a 60 A Rockwell hardness, this way the channels that guided the cables by the motor/hand crank would always be engaged, and could handle the stress of driving the 2 cables,.....if your looking for a modern solid panel donor, that's electric, and a very nice mechanical design, as well as looking almost factory,...that would be from the 80's Volvo wagon line...

Mike