NOTE: These are observations of lock behaviors outside of the specifications of the locks involved. Do not use this for in-service production security locks!
The KW1 key bitting allows a 7 depth when a lock is master keyed but is not a normal depth. The depth is .300" and that is the same as the Schlage 9 depth and using that Schlage 9 bottom pin seems to work.
Key Blanks for SC1 and SC4 seem to match a -1 pin depth of .150" and using a .150" pin works for key blanks; note however that you must use a top pin longer than .200" because that top pin will fall into the cylinder and I have used the .235" top pin for this.