being as though your finding this hard to understand.
1, ask the garage how much to fix it.
2, ask the garage how much the cars worth in its current state
3, add the 2 figures together
4, wait and see what the insurance offer to settle.
if 4 is more than 3 then it may be worth you offering the insurance 25% less than 2 to buy it back, get it on the road again and you have your reliable car back and maybe some change to tint the windows so no one can see its you driving that car.
if not then take the money and buy another car, end of