I am not sure if it helps, but the DVD1 Mk2 version (Type No 4621) apparently shares the same power supply – I must have read this in this forum at some time!ย I just checked the part number in the DVD1 Mk2 service manual and it states 8006898, which is suspiciously close!
Your friend may well be able to find a DVD1 Mk2 for spares more easily than a BS1 power supply.