this is a little weird, I went out to my shed where all the 'projects' live, and found the pot that I had taken out a year or so ago, and never found a replacement.
It says this is a Duncan electronics product, which is in agreement with what the previous requester had noted and Dan found had been incorporated into BEI.
The markings are:
2230-588-1 Of course a google search finds nothing, and while there is a range of potentiometers on the BEI site, this gets no hits.
The other thing which I find strange is that it says it is 500 ohms, NOT 10k which I must have imprinted from all the other potentiometer wind direction indicators that I've played with. And plus or minus 10%, which seems a wee bit odd.
Also when I was at the site that DanS had posted for BEI, they indicate that the range of rotation is usually in the 350 degree area, which if it is indicating a dead zone, OK, but these are continuously rotating, so that there is no stop at the high or low end, obviously. I don't know if ordinary pots can be had that way, or Texas Electronics had to operate on the ones they used to allow them to rotate without a stop.