You are certainly entitled to a share in they property or its equite. I do know that council ppurchases do have the aditional problem of a sale restriction within a certain period after its purchase (I think it is 5 years) i.e. if you sell the property within that period, you have to give them some or even, all of the equity from the sale (profit)
You need a solicitro to sort tis out for you, but as long as you are able to prove that you made payments towards the mortgage and/or the deposit for the purchase, you will certainly have an entiltlement.