I began the process of slotting the guide rails ends of the keys last night. It is, in a word, terrifying. The process is to draw two lines on each side of the original hole I drilled to place the guide rail pins when the keyboard was still a solid piece of wood. Then, I use the band saw to cut a slot using the lines as guides.
The cut results in a slot that is too tight for the pin. This means I must sand down the slot using a wee, little file. It's totally, completely nerve-wracking. In fact, I think I overdid one so that it's a little looser than I wanted it to be. Ignoring this soul-crushing event, I charged ahead and ended up with five of the 21 completed. The photo below illustrates Key #1 after notching and sanding.
I'm not sure what I'm going to do about the one that's a little loose. As you may or may not know, I also maintain a Facebook page about this project. A Facebook user who, I believe, lives in Australia gives me wonderful suggestions from time-to-time. For instance, after seeing the first photo above, he suggested I clamp a stop behind the blade so that my notches are consistent and I do not saw into the main body of the key. This is an outstanding suggestion because it's really quite difficult to see the blade's progress as I cut.
I tell you about him because I intend to ask him what to do about the loose notch. Perhaps it's not as loose as I think it is, yet it gives me significant pause for reflection. This is one of those tasks where screwing it up results in a bad, bad situation. I hope I do not have a one of those on my hands now. More to come on this after I ask him about it.