Charles Ware is at present rebuilding the 3rd oldest surviving Series MM which you may have seen in his tent at Stanford Hall. Parts are being sourced from all over the world. I recon £17k will look like small change.
Depreciation is very relevant.
You could spend £1700 on a 12 year old car and it still wouldn't be worth any more than when you started.
Spend it on a Minor and you will be adding value to the car.