After making a breakthrough getting the key to turn, I still can't get that collar off.
the special tool I ordered was out of stock, so I got a refund but no tool. I'm trying a different vendor, but meanwhile also trying to get that collar off. I've done this on a W123 and W126 and this bit wasn't hard at all. Given this W116 is a 79, it has the 3rd type of tumbler, like a 123 or 126 car.
I've tried various tools to try and grip it, removing the cluster to see if there is more access from the top (not really) or the lower trim, to see if there is access from the bottom (even less).
I've tested how far I can get the tiny screwdriver in the hole on my spare tumbler, and i'm getting it in enough to unlock the tab. So not sure why its so tight here.



