Forge Short Shifter is a cast copy of the original, with an adjustable hole for the pin. With pin set in the middle, it shortens the throw from cca 6 in (15 cm) to cca 4 in or a bit more (10-11 cm).
Anyone with decent DIY skill can take the stock shifter, drill a hole about 1 in towards the center and screw the pin back in.
+ Shorter shifter movement;
- Heavier shifting, notchy feel.
As the car ages, shifter movement may become even heavier in 1st and 2nd gears at start, as both synchros in the gearbox and (riveted) fork for 1st-2nd gears become "sloppy".
There is a counterweight on the shifter, at the opposite end from where the cable attaches. Some aftermarket short shifters lack it. This is a necessity, not a luxury, as the car ages, it makes the shifting movement much smoother. The bigger the counterweight, the better.
In fact, if you attach some self-adhesive lead weights (those made for wheel balancing) to the counterweight end, carefully to not interfere with shifter movement in each gear, the quick-shifting movement becomes much smoother and easier. It takes at least 100g (0.22lbs), but towards 150g (0.33lbs) is better.