It is odd. I'll lift up the boot and see if I can see anything. If it spins that easy, why have a diagram on the shift knob ? It's more likely to be pointing in the wrong direction. I asked my Dad if his did that, but he couldn't recall it did, but he sold his car in 1976 or so.
There is no set screw, but there is a rubber bushing inside the chromed tube below the shift knob, and the actual bent shift lever with ball end that is retained in the trans cover. It can be a b#*@% to remove - it's retained by a circlip, and difficult to remove, but it's being worn is what allows the shift shaft to spin so easily. Replace this bushing and it will still be able to rotate, but will take a lot more effort.
Many others sell it closer than Greece. If you look on sites with diagrams you can find the part number. IIRC you're going to need a sturdy circlip tool, something else to remove the old one, and some patience.
It's designed to allow the upper part to rotate, but an unworn one is stiff and makes it more difficult to rotate. You may just decide to live with it the way it is.
Difficult to remove is an understatement. I had to have a a bright flashlight, an inspection mirror, a vice grip to hold the boot fabric down on the shaft and then get the tool hooked around the edge of the gear shift shaft while looking in the mirror to get the tool even close. I got it hooked on 3 times and each time the clip wasn't shrunk down enough to lift out. The ends of the C clip contact each other. I think I would need to squeeze the clip and then get a small screw driver to hook behind it and slide it around like taking a bicycle tire off a rim. But, I already had my hands full and used my wife to hold the flashlight. Working in a small mirror was really hard to keep the tool in the right place. The space is so small, with the tool and the mirror, I don't know how I would get another tool in there to lift out the C clip. Is is really a pain.