best just to let it go... insurers want too much for them these days especially if you cant show probable cause (excessive modifications) to show why you want it back, they pay you its their car, and they would rather see it hit auction and fetch a decent price from my experiences....
up to you. they will probably want around the $3,200 mark. maybe less.
but have you got buyers for the parts? work out weather it is feasible for you first. have a scrap car sitting around feasting parts off it, or put the extra cash into the new car?