Thanks C! Actually, the tube is just fine. It's sitting nicely on a spare 2824-2 I have. I think J is correct in that the 4th Wheel pinion is broken off and needs replacing.
EDIT: Sorry, I thought you meant that the seconds hand tube from the TOG broke off. I think you are right that another seconds hand tube is stuck on there. I might be able to fix it when I take it all apart.
In the meantime, can anyone tell me if this looks like the right part from Ofrei?
ETA 2836-2 Fourth Wheel, SS Ht 5.55
Standard for the ETA 2836-2 and can be used with the ETA 2801, 2801-1, 2801-2, 2804, 2804-1, 2804-2.
FB-227/734
$9.35