You need to get the valuation done by a proper insurance valuer who specialises in classic cars. If you contact me via asklucy@honestjohn.co.uk I will dig out some contact details. However they will charge you for their services.

In terms of whether the vehicle is repairable, Category C ("an extensively damaged vehicle which the insurer has decided not to repair, but which could be repaired and returned to the road") should be the presumption in these circumstances unless the vehicle is deemed unsafe. However they are very difficult to get changed once applied. The way to deal with this is by an extensive intervention *before* the vehicle is categorised - rather than after.

Surprisingly it is possible to get a Cat B ("a vehicle from which spare parts may be salvaged, but the bodyshell should have been crushed and the car should never return to the road") back on the road but it will be almost impossible to insure and probably unsaleable.

Didn't you have agreed value? Most people do on classic policies, precisely to avoid situations such as this. The insurance company agrees up front exactly how much the car is worth, and what they'll pay out in the event of total loss.

Their estimate of the car's value at £5.5k is a lowball. You aren't bound by it and don't have to accept it.

The engineer's report is a difficult situation because you hired him, which kind of implies that you'll go along with what he says. However, engineer's reports for repair estimates are generally based on (a) fixing every little scratch and defect, even if it pre-dates the accident, (b) using genuine parts at high retail prices, and (c) high assumptions on the labour rate.

I would try and avoid the write off situation altogether. Your first job is to persuade the insurance company to value the car sensibly, so send them any evidence you can - photos of the car prior to the accident, photos of it at the car show, adverts for similar cars for sale, receipts for previous repair and restoration work done, etc.

Then, armed with your estimates of how much it would cost to fix (£3.5k, £5k, £6.5k) ask the insurer to settle for cash in lieu of repairs. If they are anything like mine when I did it, they will pay out 90% of what they agree the car to be worth. Then spend the cash getting it fixed in an intelligent way. If you know the Jag scene (I'm assuming you do as you go to shows) then you'll know how to source good parts at the best prices and should be able to find an independant specialist to do the work. Depending on where you're located, I know a good specialist in Berkshire.

In my similar (but lower value) situation, my wife had a little prang in my old Golf GTi. Ruined the bumper and a headlight, smashed the rad and fan, nothing structural). Insurance company recovered it to their approved repairer, who said the damage would cost £2k to repair. Insurers said the car was worth £500 and with my excess offered me £400 as a total loss.

I wrote to them, politely but firmly telling them that their valuation was way off and provided supporting evidence in the shape of AutoTrader ads, receipts for work done, service history, etc to prove that mine really was one of the VGC examples that would command £1,300 on the open market. They wrote back agreeing, and offered me (after my excess) £1,200 as a total loss. I wrote back to them saying I had the skills to fix it myself and would be happy to take £1,100 as cash in lieu of repairs - and they jumped at this because it saved them £100 from their revised offer.

Nipped back to the approved repairer and asked what he'd fix it for cash in hand and without the hassle of an insurance company (who'd take 30 days to pay, would quibble the invoice, etc), he said £1,000. Paid him to do the job and made a £100 profit on the whole adventure.