I'm sorry i don't have photos to add to this comment, but I have two X1/9s. On one, a PO shortened the shift lever. It is very short...like maybe an inch or less above the boot. it has a classic Fiat/Ferrari (ha) ball shift knob and honestly I've not had the nee to remove it so I don't know if it wash re-threaded, the ball epoxied or what. It does not feel anything like what Carl described, it's tight, exact & if anything a little notchy. I don't have particularly long or short arms, but the ergonomics feel fine (good, even) to me. What it is not is "faster" necessarily...for reasons of the nature of the transmission itself as described above. I'm fine with it and may not change it.
On my other X1/9, the PO shortened the lever in two ways. He raised the pivot ball on the shaft a bit (1"? more? nothing shocking) I think by heating it up & pressing it. Then he cut a bit off the top, though the cut may have been more for fitment with a taller, Momo, shift knob. It's funny...after a couple years driving the first one, this one seems a little tall to me. Go figure.
All that said, my other, earlier-owned X1/9 was an '81 in the full original trim from bumper to bumper that Fiat put on the cars in their waning years....so it had the beer tap shifter, which I thought was heinously ugly, but remarkably comfortable & ergonomically correct.