Hi Philippa, I understand how you feel.
However, if the repair is going to cost mega bucks,
and if insurance won't cover it,
and if you're not the richest person around,
and if you're ready to thow it on the fire,
(that's a lot of ifs),
howsabout offering it to a trainee instrument maker or a local technical college that teaches woodwork, as a special project?
Maybe they will make a mess of it but maybe it might be playable when they've finished and someone will have had valuable experience working on an old instrument.
I once repaired a broken guitar (my first, very cheap rubbishy one that someone knocked over) and I got fibreglass stuck all over me!
It sounded fine when I'd finished but it always looked a bit strange.
But that was 40 years ago - there's a much better range of repair stuff these days and people who work with wood have a better idea of how things work than I did back then!
Good luck,
Robyn