Buying a site by taking Certified copy of the mother deed as originals given to other buyer

Hi All, I am planning to buy a site in Bangalore from a seller who owns two sites - site no. 1 & 2. He will be selling site no. 1 to Mr. X and site no. 2 to me. The owner is telling that he will handover the original mother deed (the sale deed with which he got property transferred to his name) to Mr. X, and a certified copy of the same to me while registration. 1. Is it Okay to accept the certified copy of the mother deed (owner's sale deed) and proceed further for regitration? Will there are any legal complications involved, when I plan to sell this site in future? 2. Is it required to get any Affidavit/Certificate from the owner, stating that "the original mother deed is given to Mr. X (buyer of site no. 1), and a certfied copy is handed over to me (buyer of site no. 2)". If so, is it realy realy necessary to register such a certificate? 3. Is it necessary to include any clause in Sale deed stating "about getting only certified copies, and originals are with Mr. X", or something similar to this? 4. Will it be possible to get the certified copy of a sale deed (which is registered in June 1989) in bangalore? 5. Will the banks have any problems in giving loans with certified copies of mother deed?