The bottom line is It's only worth what someone or you, is willing to pay for it.
Mine has no replaced panels, is very good underneath as it seems to have spent a portion of its life in warmer climes (Spain), apparently the original fuel straps came undone easily, I have already removed one of the wishbones without any hassle,rear backplates are like new but not, and have been told behind the fuel tank was very good with no issues at all.
Saying that, although it seems to have an original VW replacement gearabox, a cheap spray job has probably cost me, then there's changing the original engine to a diesel. All these detract from originality which is what brings in the cash.
Then add to that the high mileage, although all wearing parts will have been replaced this still detracts from originality.
I intend to keep mine until the are £30,000 like a splitty samba unless it gets seriously bashed offroad, that's if that ever happens.
Rob.