Manifestly fraudulent Will under probate proceeding

A manifestly fraudulent WILL has been submitted for probate more than 3 months after filing of a civil suit for partition of the same property. The unregistered will has been prepared on stamp papers purchased by the beneficiary himself, on a date two days following the stated date of execution of the document. The beneficiary himself was the custodian and had placed the document before DJ Court, though it was later evidenced by one of the two attesting witnesses. This had been brought before the Court, immediately following production about 7 years before it has been presented in evidence as exhibit. Petition for cognizance under Sec.340 r/w sec 195(ii)(b) was then rejected on ground as "premature", recording the fact of the manifest date discrepancy. The only argument advanced by concerned plaintiff is that, "Will can be prepared on any paper", and their evidence has been closed without any reference to this by the beneficiary or by the two attesting witnesses he produced. What can be the best course of action now for the defendants ?