This has been a great project and it's inspired me.. showing the potential of 3D printing to make just about anything.
I bought the electronics kit from fdl1.com
As stated in the project description, you'll need to tap the screw holes and probably do some sanding here and there to adjust the fit and make things slide smoothly. I was pleasantly surprised by how well things came together and how sturdy it is with 3d printed parts.
Make sure the plunger set screw is tight(!) and that it glides smoothly. If the revolver has any trouble turning, might adjust the shape of the revolver switch holder slightly with some sandpaper - pay close attention to where it is sticking (flashlight helped) and it should be clear where it needs adjustment if any.