We may soon see the 6LXB, from the bus, powering the Milly but frankly, although that's possible, it's unlikely. I agree with radiomike7, after you've costed for collection, gas and time you'd be hard pushed to make a profit by weighing in this cab and chassis unless it was on very good tires that you could sell on. Even at the current prices, scrap dealers would expect to pay a lot less than £1750 for a proposition like this to make it pay.
TooTallMike makes a good point, while there are high scrap values and more historic vehicles in need of restoration around than people who want, or are able, to own them then some people will be tempted to scrap them rather than just leave them rotting in
the nettles. Less vehicles around MAY result in higher prices, at some time in the future, for the historic vehicles that have survived but who knows what the future may bring. It's a market just like everything else.