My post from earlier was >>50% of car value at the time. All insurers are different. That was with Just Car at the time, they were perfectly willing to pay to repair it at the fraction of insured value that it was at, but would have struggled to justify if it became any more expensive. Shannons, being another even more "classic & unusual" insurers, would and should be just as willing.
I will caveat my statement though. My repair was not at fault, even though it was front end damage like (but much worse than) the OP's. So my insurer was working for me and my interests and was willing to put up a fight against the other party's insurer to make them pay. If the OP's to blame for his damage, then he might not get treated quite as nicely.