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 5 (click to view)
ACCESSORIES LIST - 1
NOTE: The characters in the suffix column indicate the part usage. YHL ....................XX..................................A................... KANRI REF.NO PARTS NO. NO. DESCRIPTION SUFFIX 8Z-HT4-905-010 IB,YH(ECK)C 87-B30-240-010 HEADPHONE,HP-M035 87-PD3-050-010 1B STRAP,HAND A................... A................... A...................