Try USAA if you can, I hear statefarm has done ROW's as NAS equivalent but they might be getting wiser to that.
USAA does do agreed value on some but not others, they may ask for an appraisal also. The collectors insurances you can try too but they all say:
>no off road
>no daily driving
>no driving in the rain
>can only drive to and from car shows
to varying degrees.
Get whatever normal insurance you can, get the car appraised (good idea imo) and be prepared to fight it out with an adjuster with a big fat stack of backup paperwork if something happens.