In the given scenario, the person who claims that the will is fraudulent has to prove that Person B died in 1980 and not in 1981. If he succeeds in proving it, then the will becomes invalid and the property devolves upon the legal heirs of Person B as per the laws of inheritance. However, the fact that he has produced a death certificate dated 1980 raises suspicion, as the will was executed in 1981, and it is not clear why this certificate was not produced earlier.
To counter the claim of the person who has filed the suit, you may try to obtain evidence that shows that Person B died in 1981 and not in 1980. This may include hospital records, medical certificates, or affidavits of witnesses who were present at the time of death. You may also try to cross-examine the witnesses who are being produced by the other party to prove the death in 1980.
If you are unable to prove that the new death certificate is not correct, you may try to explore other legal options to protect your property. One such option is to claim adverse possession of the property. However, to claim adverse possession, you need to prove that you have been in possession of the property for a continuous period of 12 years or more, and that possession has been open, peaceful, and without any interruption. In your case, you may be able to claim adverse possession as you have been in possession of the property for a period of 28 years. However, adverse possession claims can be complicated and are subject to legal challenges, so it is advisable to consult a lawyer who specializes in property law before pursuing this option.
In conclusion, to protect your property, you should gather all the relevant evidence to prove that the will is valid and that Person B died in 1981. You may also consider claiming adverse possession if you are unable to prove the validity of the will. However, it is important to seek legal advice before taking any legal action.