Rolleiflex 3.5f front lens group removal

[ed_skibeki]

I mistakenly posted this earlier on the "modern film cameras" site by mistake. I'm posting it here again, hoping that's ok.

 

I recently picked up a late (sn 355...) Rolleiflex 3.5f with a Zenotar lens.

The front lens group taking lens seems to have haze on the rear element facing the shutter that I'd like to clean. I understand that the group simply unscrews with a rubber friction tool, but I'm not sure which surface to torque against as there are 2. One is a ribbed trim ring and then there is a separate inner name plate trim ring with the lens name and serial number on it. The inner trim ring is about 30 mm and the outer about 35 mm. (Photo added for reference)

 

I don't want to be torquing the wrong one, so ask here, does anybody know which one I'm after?

 

Thanks in advance.