You need to address the situation of the value with the insurance company or your broker, the engineer who valued your car won't be aware of the agreed valuation you have in place.

A payout all depends on the circumstances mate, the Third Party Insurers dragging their heels usually hinders claims a great deal.

How long is a peice of string i'm afraid mate, I settled my own claim in 3 weeks from having the accident to having a cheque in my hand, but then I have known them to take 2 years plus!

HTH