[Elecraft] K3 Button Box

[P.J.Hicks]

Other than an excuse to build something there might be another way. I haven't used one on my K3 but I do use one on my KX3. 
I have a Genovation model 684 serial programmable keypad that has 24 keys. One of those is used as a shift key so I have access to 46 macros at the touch of a button. Each macro space will hold approx. 180 characters so there is plenty of room for elaborate macros. Programming is a snap with the graphical interface supplied as is a cable. Cost was about $90.00 as I recall. There is a model with 35 keys. 
  
Might be the answer to your needs. 
  
PJH, N7PXY