I didn't know you could do fiberglass molds... but if you're interested, you could cast the shifter can but not put a hole in the top. Offer them to people with 5 speeds and let them locate the hole for the rubber grommet. They would look stock, but solve a problem many are faced with. I had a line on a guy who could do such castings, but he lost his access. ..
You could even cast it shorter to give more throw room for the shifter..
Just a thought......
and hey, I have some wire(s) for ya, next time I'm in the area.