Thanks to Annie B. for her tip about putting the straight part of your kento farther about 2/3 of the way down from the “L” cut. That’s great advice for getting accurate registration and I plan to use it for these prints!
I am also using a slightly modified version of a tip that I learned from Graham Scholls DVD: The Art of Coloured Woodblock Printmaking (thanks Graham!). He advocated using a sheet of frosted mylar over a sheet of graphite carbon paper facing toward the mylar. By taping these layers over a carved block, one can use a baren to take a rubbing of the block without all the mess of inking it up. The image will transfer to the transparent mylar which you can then position over your next block to check for accurate registration.
Here are some images where I have actually made a graphite rubbing over a blue transfer paper rubbing to check the alignment.
I take this one step further by actually placing the corner of the mylar sheet into the kento registration cuts of my first block. Before carving the kento into my next block, I line up the second carved block with my transferred image of the first block. Once I get them perfectly aligned, I tape down the mylar. Then I take my kento knife and place the flat edge of it right up against the mylar corner and press down to make the initial corner kento (kagi) cut. I do the same thing 2/3 up the side to make the side kento cut (hikitsuke).
I have now finished all four blocks of the first print. I will post a test print soon.