Well bad news and good news I suppose. I did send the lens to Eric and he examined it and informed me I have separation of lenses in that rear lens group
So that’s that. First time I ever had such an issue.
Good news is that I found another silver MIJ 77mm with serial number in the same range and with green bag, box etc. Price was too good to pass up (less than what I got the other one for many years ago) and the condition is exceptional.
So the 3 princesses are still intact ( I can’t have an incomplete set haha ). Thing is now…do I just keep the other for parts, try to eventually find someone who can do the repair (and at what cost though) or maybe eventually come across a beat up 77 for cheap with intact rear element to salvage and replace the separating one with. IDK just ruminations