Linked Files Libraries Schematic display

I have a large 3D model blend file of 90MB (not built by me) and I need to understand how all the separate objects materials etc etc are linked.

Primarily I need to rename some 160 separate objects presently listed as numbers and call them by their technical names with which I am completely familiar, however I do not want to risk upsetting any links etc etc.

I believe there used to be an ‘’OOPS function’’ ?? in early versions which showed a schematic of linked files and I was wondering if there is now something similar or more advanced ( perhaps an add on) that will open up a finished model to show a schematic of all the elements and how they are linked.

Presently using V2.79 but also starting to get familiar with 2.80 and any advice on this query would be extremely helpful.