It is very important to fallow the directions in order. To make things like cuffs, sleeves and such easier to sew the order things are done in is different from that of full sized clothes. ..
The duster and trench coat are simular to the PJ top.The difference being the duster and tranch coat are larger , longer and the duster has 3 more pices.
If you have used the PJ top pattern you should be able to use this one