You've got to stick with it with the insurance, just don't let them write it off, when they realise you're a massive pain in the arse for them they'll just do what you want. It's gonna be shit though as it's probably the last thing you want to do at the moment, but you have to keep mithering them that it 's not a write off.
I had a similar situation a few years ago, in the end they got that tired of talking to me they gave me a 'cash in lieu' offer. Where basically they gave me the cash up to the value of the car minus a few fees or something, to get it repaired myself, and the car wasn't a write off. car was worth £2k and I got £1.7k, the repair cost about £1200 (although they priced it at like £3k) so had the the full car resprayed for a little extra.
Depends on who it is you can end up talking to the engineer, and if you explain its a classic and you'll do all the repairs yourself he'll most likely help you out. This happened when my MX-5 got (proper) written off, the guy ended up saving me about £500.
You should be getting a big payout for a smashed pelvis as that's a nasty injury, it's probably a little late now but you want to avoid telling your insurance about it if you can and claim of the other drivers insurance, that way you don't get a 'non-fault claim' on your record, which I don't care what they say, it defo adds to next years premium. But probably not really applicable in your case.
All the best mate. hope it goes well that damage is nothing, hardly even call it damage! I'm sure the car will work out in the end fine just a nightmare getting there!