If your handy a good service manage can pull the pieces you need and circle where they go on a picture of the valve.
I worked on the valve on a 1660 this summer and that's what was done for me. It was a few o'rings (new parts guy mixed them....), two different sizes of the plastic poppet mentioned above and I also replace one of the armatures that the coils go on.
That one little bitty o'ring was fun and it took me a few minute to sort out the o'rings.
RT (my 2 cents. hope this helps.)