Recovering corrupted iPhoto 9.1.4 library from Macbook Air'11 2011 with OS X Lion

Probably I'm not alone who is facing this problem, so the answers with possible solutions will be very useful. At certain age time starts to run like a crazy and you only saying oops! when you find out in 2025 that what could be done easily even 10 years ago, now seems impossible, so congratulations, you dinosaur haha.. Ok, here is the challenge:

I have a bunch of media in my old iPhoto'11 which I was willing to transfer to newer Mac for ages, but was postponing, being busy with life :) No back ups. Files in iPhoto corrupted, as well as the entire system, cause once, in 2021, being an idiot, I tried to install Yosemite, but with no success for whatever reason, it just messed everything up and notebook died. Yes, I know I am my own trouble, because I should have copied 6300 pics and vids before doing this. After that I installed Lion back via internet recovery. But still many things were not like before, including iPhoto. I again didn't have enough time to deal with it in 2021, so here we are in 2025.

So, what attempts did I make (to prevent you guys from advising things I've tried already):

1. Naturally, tried to upgrade iPhoto hoping it will fix the issues. Downloading iPhoto upgrader 1.1 app and 9.4.3 or 9.6.1 updates,which are now available from Apple, didn't help. Upgrader was installed successfully, but not the updates. I keep getting a message that at least 9.0 should be installed which is ridiculous cause I have 9.1.4 but somehow it is not recognized. Tried to install Mountain Lion, which is also available now - zero result, apparently my OS can't be upgraded either.
2. iPhoto Library Manager (bought in 2021) helped me a lot to retrieve bigger part of the pics but not vids. It let me rebuild part of the library fixing the files, so I could copy them to external drive finally. But in process it kept showing message "can't be copied because of insufficient space on the disc containing your iPhoto library". I just kept pressing "ok" on that msg and the process continued. It only allowed me to rebuild a certain portion each time, so I did this few times, rebuilding to a "new library" and deleting previous "new libraries" that I've already copied and same files in the main library to avoid the mess. It took ages. Needless to say, insufficient space message is nonsense, there is more then 200GB available. It's just iPhoto or system corrupted and not able to calculate the space properly, I guess. At some point iPLM simply didn't allow me to rebuild anything else, remaining files were too big. Dividing events into 1 video per event didn't help.
3. Small tricks like booting in safe mode, reinstalling mac os x, NVRAM reset, disc or permissions repairs in utility, cleaning caches and unused apps removal - nothing helped. Tried external start-up disc with OS X M.Lion 10.8.5 on it - still no changes, didn't help the copying process.
4. Tried to back up with Time Machine (cause it's supposed to back up even corrupted files), so I could try and fix it on another Mac with recovery program - another fail, back up just stopped.
5. Downloading good recovery program doesn't make any sense even if I'm ready to pay for it - old macbook can't open AppStore or app website to make a payment, and I'm not so sure - if I purchase it with a working new notebook, will the licence let me to pass the app to the old one? One would say just connect old macbook as an external drive to the new one via thunderbolt, so the recovery app could see the location of the files. Haha, tried that, my new Mac M1 with Sonoma crashes and restarts every 2 minutes if I connect them like this. I didn't want to risk my new Mac's health with such a torture, so immediately stopped :)
6. Unfortunately I can't copy files directly from Masters folder, because as I mentioned above, they are corrupted and need to be rebuilt first. If I try to copy them one by one I get the message code -36 (file can't be read or written), or code -43 (item can't be found).
7. I was reluctant to use iPhoto's built-in repair function until I tried everything else, because I thought it's probably corrupted too and I was right! I did it as a last resort, and I guess I just buried my iPhoto completely.. :((( It was stuck on "database repair" for more then 20 hrs (remaining files size is only 16GB) and then macbook just crashed without self restart. I started it, took a look in the Masters folder, all videos are there. iPhoto app when opened just showing empty folders, same with iPLM.
8. Probably instead of iPhoto self-repair I should have tried to divide the main library into few smaller ones, so iPLM could probably let me to continue to rebuild.. but good thought always comes afterwards, when it is too late..

So here I am, with my non-techie humanities-filled brains, exhausted, out of ideas, with no less then few precious days wasted on this trouble.. Can anybody please give a good advice if anything else can be done??

[Edited by Moderator]