Alex, I see the issue very clearly. Trying to balance things that are not directly comparable, and the mix includes the great unknown that is the future. What does the future hold for the value of 240s? If you part with it will a replacement cost an arm and a leg? If you store it will it deteriorate? When might you fit that turbo? And indeed all those questions.
There are two definite positives to keeping the car if you can. It is a car that you know, not someone else's problems bought by you in the future. And. It is a 240 !!!
By the way, could you have two cars? Would the 240 be cheap to keep if if is second/classic on an insurance policy? Running two cars might be cheaper than well ventilated secure storage. And. Every so often someone has an interesting time
re-commissioning a stored car.
Just my three farthings worth.
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