Personal experience, unfortunately dealing with this twice in the last three years, I've ran into the following:
Insurance companies will adjust the value if you can provide reciepts of work done OR the purchased items on the vehicle. They will than pull KBB & local area's and do value. What unfortunately you have to watch for is the amount valued by a shop, and you can go to MULTIPLE shops, to get a quote to help adjust your value.
Once you get insurance quote's I will gladly assist in giving my personal experience. In my build thread is my unfortunate Tacoma death =(. I purchased it for 35k, put 4k into it(had receipts provided to the insurance agent in charge). A year later the accident happened and since I had one of the 100 Tacoma's made with the features, they couldn't find one but a 'close' one near by and kbb caused them to give me over 35k for mine. Now I paid off what I owed and pocketed the 2500 left over!
Previously before that I had a VW and that backfired, stupid VW. They wouldn't give me more than 22k, and I owed 28k. I had GAP so, that paid for me buying GAP for the rest of my life =)
Before that I had a later rear end me sitting still in my 92 Toyota with 300k on it, The damage was 700.00 and the vehicle bluebooked at 600. They wanted to total it so I went to about 5 shops till I found one who gave me a 300.00 quote(that was them doing it also with reman parts).
So, in that regards things can go many ways. Educate YOURSELF, before doing any talking to the insurance agent. They also will have a base and max, be patient and it will work out. Let us know and if you want to shoot me a PM i will gladly give you my e-mail.