Even before I got my Vintage Speed shifter I was bothered by the fact that the rubber boot is not attached at the bottom.
I spent countless hours searching online for a replacement. I found one I thought would work and I designed and had 3-D printed a piece to retain it at the bottom. Unfortunately, that piece obstructed the full movement of the lever. I bought a 356A boot but it was way too small. For a while, I use the top part of a 911 boot but it looked too big.
Finally, bought this CV joint boot and used part of it. It is very flexible and the bottom stays in place without retaining it. The top opening is bigger than the shifter shaft so I cut off the top of the original boot and put it inside the top of the CV joint boot. I should glue it in place.
The boot is actually black even though it is blue in the photo with dimensions.