Really sorry to see that Rich but glad you're okay and nobody was hurt.
I'd definitely consider removing anything though that isn't "technically" insured, ....E.g. If you've a thick 350Z boot carpet or some nice car mats then I'd take those out to sell on. If you've an aftermarket gear knob and still have your original then I'd swap those around also.
Might be worth checking firstly with some on here who know more about insurance policies/legality than me but I'm pretty sure legally there'd be no issue with you doing that, although it might be one of those grey areas?!
It's hard to tell exactly where the line is drawn between personal possessions you can remove from an accident damaged/written off car and those parts insured or now owned by the insurance company after a car is written off.
I know taking your engine out would definitely be taking the p*** though.