It is so frustrating the insurance company will never give you a figure that you will be happy with and truly reflects the condition and work you have put into a car. My advice would be to take the money, take your time and find the best puma you can (you'll know exactly what to look for rust, cam-belt, oil etc.). You'll miss your old one but if you get yourself a really good deal you'll love the new one just as much!
Good luck with whatever route you choose to go down!