If you try to build an engine without caring for new stretch bolts and not paying attention to details like genuine gaskets, sealants, torque settings - you will have a disaster - more called "garbage in garbage out" - aka - shilcone toob + paana + taami + hathora rebuild.
Its pretty funny that the D series engines are known to spit in the eye of satan while running with little oil and water and still being able to get work done. - They are pretty dheet.
The pictures show a leaky valve cover gasket which has been ignored for tens of thousands of kms. First order will be to remove the head and check the block for corrossion, if its shot - then a new block is required. Its 90% of the fault in Pakistan because people think that "coolant" is a "bewaqoof bananay ka tareeqa" - in rebuild the machinist says he will weld new "silver" (yeah right like he's going to weld chaandi to your engine) - and then reface the block and you will have to use a 4mm thick headgasket.
such jobs end in tears - do the job once and do it correct. A car is a transport machine - it should be reliable