léonie,
What a coincidence that you answered my post - I just found a script by Toad based on another script by you to sequentially number titles in Photos albums. I used the script to number photos for this trip. As you noted in one of your posts, the script does not work very consistently. I had to run it several times to get through all 293 photos from my trip. I had another script written by someone else for iPhoto that always worked quickly and perfectly. I put in a request for Apple to create this capability within Photos - I wonder if/wen they will ever do it.
Are you in Germany? I just passed trough the Munich airport to get to Copenhagen and then to Bergen, Norway. I think Munich is the best airport I have ever been in.
The problem with copying my Photos Library from my Mac Air to my iMac is that then I would have a separate iMac Photos library for every vacation. I want to get everything into one library. I can open the packages in my Mac Air and iMac Photos libraries to see all the individual folders and files. There may some way to copy just the right files for the original and edited photo versions from my most recent vacation from the Mac Air Library into the iMac Library, but I have no idea which ones are needed to make it all work properly on the iMac, so I am not going try.
For now, I will just make do with having only the current state photos in my main iMac Library. I hate to lose the unedited originals, but I am not a serious photographer and these are just vacation photos so I can get by with just the current state versions. I still have all the originals on my camera SD card, so I can save them in a separate folder if I want to. However, they would not be linked to their edited versions in Photos, so I'd have to edit each photo again from scratch even if I just want to make a slight change, like getting back some of the cropped-out image.
I'm surprised Apple didn't make it easier to transfer both the original and edited versions of photos in a single export step.
Thanks for responding. It was great to hear from someone who wrote the helpful numbering script.