Strange pulley bolt on dura ace mech

Hi guys, I've had this 7800 mech for a while and always been curious about the strange pulley bolt on it. I don't suppose any of you have ever seen something like this? Can't fathom what the threaded stub is for?!
When removed it looks like a proper pulley bolt with the chamfer so it's not something that someones bodged in! I've just never seen another one like it on a dura ace or any other mech. Cheers in advance!

1 Attachment

Bodge

Chinese copy

haha i thought a bodge too at first but when removed its a nicely made part with the correct chamfer angle for the cage bolt hole. I'll remove it and get a picture :)