Paul, here is an old post by someone looking for instructions for a Wasco timing fixture. Someone on this thread posted a pdf on instructions for this timing fixture, and bobH mentioned those instructions might be helpful on his Chec-Rite fixture. So maybe a quick pm message to bob and he may be of some help to you on what you are looking for... worth a try.
https://www.fordbarn.com/forum/showthread.php?t=67917