The service manual is a good quality scan of the Panasonic NV-850, which is electrically identical to the Philips VR 6920, but mecanically just nearly.
The service manual is a good quality scan of the Blaupunkt RTV-404, which is electrically and mecanically identical to the Panasonic NV-830.
Text excerpt from page 2 (click to view)
EXPLODED VIEW AND PARTS LIST
NOTE: � Items marked �*� are not stocked since they are seldom required for routine service. Some delay should be anticipated when ordering these items. � The mechanical parts with no reference number in the exploded views are not supplied.