The arrows indicate that they are aliases, not the real files, don't they?
Where is your G drive backed up to? Have you checked the backup drive to see if you can open them from there?
Well, you should definitely try it in Photoshop first. If, after a few times, you feel it's not working for you, then cough up for a subscription.
https://www.damiensymonds.net/2012/05/create-your-own-wall-guides.html