911 SC how much is she worth?

[nigel911]

I'm thinking about selling my lovely SC. But really do not know what she is worth.

Here's some details:
911 3.0 SC Coupe
Guards red
Brown/tan pasha interior
1983 (A plate)
Original - i.e. no modifications
FSH - by independant Porche dealer for last 9 years
Recent 12K service, 4 new tyres
140K miles, 60K on rebuilt engine.
Generally in very good conition.

Here's the bad stuff:
Heat exchangers gone
Front wings rusty
Gearbox on it's way out.

Dealers have een saying between £5k and £7k without seeing it.

What do you guys think?

Many thanks,