Not as silly as it seems Dan, there was a discussion recently on the E type forum about the repair costs of classic cars now easily exceeding the value of the actual car. The owner of a rare classic could in effect be entitled to have the car restored to pre accident condition not necessarily "irrespective of cost" but up to and maybe more than 100% value of the car. Unfortunately in this case the OP would probably be hard pressed to prove the rarity value of his car or that he couldn't find a similar one with the money the insurance paid out.
Back to the OP, sorry to hear what's happened and hope you get it all sorted.
its not only classic insurance situations you can recover > 100% of market value
if its no fault goto an accident management company first and inform your insurance you have done so with zero cost to them
if you go through your insurance first to claim they will most likely issue a write off on the car (esp 350z) which will stay with the car even if you change your mind and go elsewhere to progress repair/recovery