I gave up long ago, Bose does not understand that the market value of the aircraft is what someone will pay for it, not what the vendor thinks it is worth.
If the asking price was 20k and he buys it for 18k then its value is 18k. If he offers 18k, his offer is not accepted, and it's subsequently sold for 19k then it's value is 19k.
It follows that you can't determine the market value until you've sold it (although you can have a guess at what it might sell for).
As for the concept of the engine fund being a liability, I'd be delighted to offer to take such a liability off anyone's hands for say 50% of the value of the liability? The fund itself is an asset, held for the purpose of meeting a future and as yet uncrystallised liability.
An understanding of basic accounting, the concept of Sales, Purchase, Income, Expenditure, Asset and Liability nominals and how they build into a Profit & Loss account and a Balance Sheet would be helpful if people want to pontificate.