compare the cost of rebuilding with cost of swap.
swap means you are not sure of engine health, what if that will give up in next 2000 kms? what would be your financial dent.
if am in your place, I will find a new mechanic (a baloch owns honda bike 2S dealership in rizvia society nazimabad) for such rebuilds. I know him since 1980's, his 2nd gen is now running it.
rebuild with correct new parts. engine will not fail.
waterpump FB area market is full of crooks. Naseem 0300 2865710 try to locate him he may help you though he has left that market but work privately