Best value might be to first jack the roof out the best you can. Then take the car to a trim & upholstery shop that can install a thickly padded vinyl roof to cover the ripples left in the roof. Stretched tight, you will not see the imperfections of the roof straightening. It will be a unique 242 that you can brag about how it even survived a tree falling on it. Good folklore requires branches to turn into tree trunks. But I'm not joking about my idea on the roof repair. It is what I would do, especially with a rare 2 door.
--
'89 silver 244DL in Milwaukee WI

1. I'm with the other poster. Push back at the other ins company. Of course they'll say that. Involve your own insurance folks.

2. I bought a 240 w/ a crushed roof not long ago, jacked it out (in the roughest possible manner) and drove it until it failed mechanically. But there was no damage to the door pillars. You didn't say how extensive the damage was.

I replaced a roof on a Willys wagon a few years ago. It was a lot of work. I personally wouldn't bother to do it on a 240 but that's a matter of preference. OTOH, some friends who do body work think nothing of cutting a roof off car/ truck A and welding it onto B.
--
85-92 240s/ 245s - parts cars & drivers

"The insurance company of the tree owner says they have no liability for falling tree branches"

Are you sure about this? I suggest you pursue this with your insurance company and sick them on Allstate. It may be worth the fee for a consultation with a lawyer. A property owner is responsible for maintaining his property such that it is not hazardous to others.

A lot depends on the exact nature of the damage. If it is just the roof panel that is bent down in the middle, and the doors stlll open and close, and no glass is broken, it should pop back out fairly easily. Though the car won't look very good, it will be usable again. If the door or window openings are distorted, it's a much bigger job to fix, and will probably require a roof transplant from another car. This is a very difficult job, and requires careful attention to the welding involved, to ensure the structural strength of the repaired vehicle. If it is this bad, but the windshield area is intact, another possibility to consider would be making a custom convertible. This has been discussed before on this board, with considerable debate on the amount of structural reinforcement that would be necessary in the floor and rocker panels to hold things together with no roof.