I appreciate a fellow item completionist!
I don't have a list yet, nor have I counted my items, yet.
I also scroll through endless wiki pages, and cross reference with my (now BIG) chests.
Did you take everything out of the catalogue and put them into chests? Because I didn't do that. (I just figured it would be okay to have the catalogues themselves, since the items are all in there. I may regret that.) Since many items were added to the catalogue, and some removed, it would be another huge undertaking to figure out what's new to 1.6.
I DO keep my 1.6 items separate from my pre-1.6 items though.
I only have my one original farm, (plus my 7 week joja achievement farm, which has nothing notable) and I made a couple of naive early game decisions, resulting in a permanent loss of potential items: 1-I sold my mines weapons, which are supposed to be available at the Adventurer's Guild now, but aren't showing up on my ps4, along with the Work Boots. 2-I chose the mushroom cave instead of the bat cave so I have no silver or gold quality salmonberries. I'm not on the Beach farm, so I don't have the thing you can fish up there. One can only trigger Penny's 14-heart cutscene once per file, to the best of my knowledge, so I'm missing a couple things there.
I don't play multiplayer, so I only have 1 of each Legendary Fish (which are all now normal quality) and no wedding ring.
I'm FAIRLY confident that I have every possible pre 1.6 item that I CAN get though, with the exception of the Junimo Kart Arcade System.
Sorry that I don't have a list. It's gonna be hard to compare notes with over 2000 items! Don't forget the Ginger Pickles!!! :)