Verify papers from relevant documents. Seems engine is swapped. Don't know about its fitting. Check is seating position from the pics that doesn't looks comfy.
This bike is susceptible to being stopped at each chowki so make sure that you yourself verify documents from relevant authorities. And ensure that is not stolen bike. Kis city ka number ha?
See engine number (written beneath gearshift lever), chasis number matches that mentioned on documents. Chasis number is engraved on the neck of the bike.
Regarding parts availability you will have very hard time finding them. Mechanics will charge hefty amount for small repairs. And will mostly be juggar if they work they work otherwise kaput.
Also Chek for vibrations as this seems dual cylinder setup to Chek if both cylinders are in balanced.
