To check if it is high density or low density, check if the hole on the bottom right (NOT the write-protect tab on the bottom left) is present. If the hole is present, it is a high density disk. If it is not present, it is a low density disk.
You can image the disks using Disk Copy on the Macintosh II. From there, copy to your macOS or Linux system and check the image using various utilities. You may need to convert the Disk Copy format to another format using "hdiutil" on macOS.