It worked, it worked

Took a while to file that washer just right, and it took a lot of force ,
but the remains of the bearing finally squeeked out of the end of the
crank.

I promptly hammered in the replacement bearing.

Next question.

The gasket kit I have includes 2 sets of 4 metal sealing rings.  The
thicker, less flexible rings go  -between-  the top of the cylinders and
the heads.

My question is about the thinner, very flexible rings.  These could
conceivably go -around- the crankcase end of the cylinders, or -around-
the head end.  Which is the right location, and are these rings necessary?

 Peter Williams
73 Westy (1700)
California or Bussed