Yeah, those are neat looking things. I have one of them in my tube collection. Yours apparently took very few "hits" over the years, as the glass isn't blackened and the graphite balls look to be in good shape.

BTW, the "KR-85" marking on the base refers to Krypton-85, a radioactive gas. The tube contains a small amount in order to stabilize the triggering voltage. No hazard at all in a sealed tube, but if it breaks, open the window and air out the room.