I worked for an insurance company and I settled diminished value claims on a regular basis. Since, I've gone into it full time & started my own site to give appraisals.
It sounds like you have a valid claim to me. You just need to know that dim value is tough to negotiate just because of the wide array of opinions on it. You should get an appraisal from someone and present it to the liable insurance company along with a demand letter.
Then, follow-up by phone a few times until you get a decent offer. Considering that your repairs were so high as a percentage of your ACV, your dim value claim would be higher.....maybe 15-25% of the pre-loss value.