1970 Duster Alternator Pulley Alignment

You have the correct water pump/fan pulley, but you definitely need the triangular bracket that mounts to the water pump and hold the pivot bolt for the alternator... There is no need for the stack of washers on the lower end water pump hole, the triangular bracket bolts directly on the water pump and the slotted bracket goes on top of the triangular bracket on the right (passenger) side lower water pump bolt...

The way it's configured right now, there is no support for the alternator pivot bolt which is absolutely necessary to keep it from vibrating and fatiguing and breaking the alternator pivot bolt... The alternator pivot bolt needs the support of the triangular bracket...

You also need to get rid of the double groove alternator pulley and get a single groove alternator pulley, whether you get a new alternator or just change the pulley...

That is definitely a hack job... But you can fix it with the correct parts...
The OP's water pump pulley is an A/C one. Compare it with yours. The offset and diameter are totally different.