RandyT, Have you already had a bunch of these pre-made, or is it possible to have them made without the additional 1/4" at the end?
These have already been manufactured in a relatively large quantity.
This seems like a simple problem to fix, however. Just take the
top spacer that originally came with the joystick and cut off a 1/4" chunk. Sand it down to about .165" while making the side you cut nice and square. Add this to the spacer at the top and all should be well.
You may want to test fit it a couple times during the sizing (sanding) process to make sure you don't go too small.
I don't own one of the adapter kits, so I don't know for sure that this would work, but I don't see any reason it shouldn't. It'll also make the stick a little taller, which may or may not be a good thing depending on your preference.
RandyT