Here is a list of ressources to analyse some weird machines.
TLDR : Take out the SD card, make a forensic copy of it, and analyse/carve for pictures.
Take out the hard drive, make a clone of it on a similar 2,5" hard drive, put the cloned HDD into the console and then open all interesting menus like browser history, chats, media and take pictures or a video of all of it.
TLDR : Extract the memory stick, make a forensic image of it, and analyse/carve content. You will also find some historyX.dat files that contains web history inside PSP\SYSTEM\BROWSER\ of the memory stick image. historyi.dat contains inputs from the user, but not necessarily visited websites. historyv.dat contains visited websites. historys.dat contains search entries entered from the PSP Home Menu.
Use QCMA to backup data from USB using the custom MTP protocol of Sony. You can extract apps, images, musics and videos. The web history must be manually examined on the console, same for messages.