The top wing nut and bolt is not stock, and the other 2 are questionable.
My guess is that this is a Pearl since I have a similar hi-hat stand part that is definitely Pearl, and the style is the same. But I read that it could also be a Tama, because both companies were copying Slingerland at the time.
Only one of the top arms has some remaining rubber, and the rubber feet are long gone.
Click on the thumbnails for full sized pictures:
