I've always viewed the "rock solid residuals" as a bit of a wish, rather than a reality.
The CX models changed everything, then Morgan Motor Company changed ownership.
In November 2014 I paid £65,000 for my then 9 month old Aero Supersport Plus 8. What is it worth now?
Talking to dealers, anything from £50,000 and upwards...I can't get a clear answer, but probably close to what I paid for it.
Even if it is £50,000 that is trivial depreciation: anything else bought for £65,000 in 2014 would be worth close to "Not a lot" in 3023.
This 2013 Plus 8 has only covered 17,000 miles and retails at £69k (trade probably £60k ? ) I assume its the same car as yours Peter ?
https://rtcc.co.uk/cars/2013-morgan-8-4-8-bmw-v8/