Excise has returned files of vehicles After 2003 Model , Before 2003 Model the files can be obtained on request of owner.
That file contains info regarding purchase date / Purchase History , Model etc . so if it has return file no need to verify through Excise, just verify through File or if more concerned than check online. But Do get it cleared through CIA .
Also when you give biyana(Do not give more than 15,000 , i gave 10,000 :D) , Do Get car Keys and NOTE Millage + Battery + Tyres and the parts which can be easily changed and Do Dealer Let know that you Have noted down all of these items.
I will give you Copy of papers or Original ( but mostly they give copy) . No worries just get it cleared . Than he will have his own Made Forum which will need your ID Card Copy , Sellers ID Card Copy , Thumb Impressions and 1 GWAH ( witness) from both sides, Through Dealer you do not need any Transfer Latter.
After Giving Full payment Get your car , and get it Transferred by you or Give 3,000-4000 to Dealer (preferred to give him , as he know what to do etc) . That's it
Hope i helped 