You are claiming title under a 1967 contract
Even court has declared that your possession is in part performance of contract
Once there is a contract under which a party claims, that party cannot take the plea of adverse possession, because the pleas of right on basis of contract and right on basis of adverse possession are inconsistent pleas and both cannot be taken together ie the party has to rely on anyone plea only
If you claim right and title by adverse possession then you will have to renounce your right under the contract and the court decree saying that your possession is in part performance of contract
Since the limitation period for filing a specific performance suit has already lapsed, you cannot file any such suit now
So you will have to renounce your claim under the 1967 contract and instead base your claim on basis of adverse possession
Under the doctrine of adverse possession you can either file a suit seeking declaration of your title or you can defend your title if the original owner files a suit against you
Not possible to refer caselaws when the client has paid a pittance of Rs 600 only for the query. Case laws and legal research takes lot of time to find