The value of all diecasts depends on a few things; mainly the model type, whether it's in it's original box and the condition of box and model.
BOXES If your model does not have it's original box, this halves it's value.
CONDITION. 1 little paint scratch/chip de-values it considerably.
I find that John Ramsay's British Diecast Model Toys Catalogue is the best Price Guide to use. It is available from Amazon.co.uk for about £14.95 GBPounds.
If you want to sell or just value your items, why not try EBAY auctions.
Check out items like yours that have sold recently to give you a value,
then sign up to start selling!
Please do not deluge the forum with valuation requests.