Well, my Australian dude on Facebook responded and suggested that I simply steam the key ends over a pot of boiling water and use a little pressure to pinch the slotted ends together if I have made them too wide. Another easy approach to a gut-wrenching perceived problem - he's the one who suggested I use a stop on the band saw deck to prevent me from cutting too far into the key bodies (photo below).
This required me to use one of the previously slotted keys to set the stop. Whenever he makes suggestions like this, it leaves me wondering about myself. Perhaps I make things too difficult at times (my wife would wisely refuse to answer this question)?
Before slotting each key with the band saw, I draw two guide lines and carefully cut inside each as in the photo below.
This requires me to file less than a millimeter at a time to ensure I don't make the slots too wide. You can see the file I'm using in the photo above - it's between the pencil and key; it's one of the many I purchased from the high school friend I mentioned in a previous post.
As you can see in the photo below, the keyboard is coming along.
Once I've completed the slotting of the keys, I will notch the ends of each so they are easier to slide back in should I need to take them out for maintenance at a future date - more on this later.