There might have been more uni-points than that one, it's just the only thing I found on uni-point radial arm saws. I suspect it needs a little restoring. From what I read, the rights to the saw were sold to northfield foundry and machine in 1963, so it has to be older than that.
Seriously, I'd have to rent equipment just to unload a beast like that, could never justify the floor space. I'd love one if I had room though. My gues is they are a little outdated by the modern slider.