Many of my answers, here on AB, are based upon simply Googling for information but I've actually been looking into a similar situation today for a friend. She's a lady 'of mature years' - 76 actually - who is trying to work out what to do with her very elderly campervan, with insurance and an MOT until next month, but no tax (subject to SORN).
I've spoken to DVLA today, who've confirmed that (although the vehicle could be driven to a pre-booked MOT test) the campervan can't be driven to a scrap yard about 6 miles away unless it's taxed. (Given that the maximum penalty for driving a vehicle subject to SORN on a public road is a £5000, plus a possible prison sentence, it seems unwise to 'risk it'!).
I won't waste your time with all of the options which I've explored (which won't apply to an uninsured vehicle without an MOT certificate). I'll simply provide you with a few figures:
The scrap yard currently guarantees a minimum payment of £110 for any vehicle which is taken into their yard. (2½ years ago they were only guaranteeing £50 but, when I put my saloon car onto their weighbridge, I got £60 for it). So, based upon weight, it seems likely that my friend's old Sherpa van (yes, it's THAT old!) would be worth, perhaps, £130-£150(???). When I phoned the scrap yard and explained that it might not be possible to drive the vehicle to them (even though that remains one of the possibilities which we're still exploring), they offered to collect it from my friend's home and to pay her £100 for it.
Chris