Inventorying my loose round B/W tubes, it would seem that (looking from back) the convention was to position the anode at 9-o'clock, and the center pin of the 5-pin group (pin 12) at 6-o'clock. The overriding majority of my stuff is like this, and I assume it's the norm. Your tube is correct and I guess the wires won't go where I thought they should.
I have 3 tubes that do not follow the convention (with anode at 9:00, they are at 7:30, 3:00. and in one of my GE810's, at 4:30). The two tubes at 7:30 and 3:00 are rebuilds (seam on neck). So at least some of the tube rebuilders out there were not as diligent as was Scotty. No plans to remove CRT from the 4:30 tube to check, but I'll assume it's a rebuild too.
I didn't pull my pristine 810 very far away from the wall and checked behind with a flashlight (as you can tell from the post it was 2am). I must have had my left and right reversed, I checked for the wires and hole clearance, and then wrote my report. But as it turns out on closer inspection someone carved the slot larger to clear the wires, in the 6-9 quadrant, sometime in its ancient history. It looks like the tube in it is normal too.
So I retract my suggestion, lesson learned.
