When doing any sort of data recovery or digital forensics, the first step is always to make an image of the disk and work from that. You don't want to screw up the original media, and when you're dealing with something old and slow like a 3.5 floppy disk, the less time you have to spend using the real hardware the better.

As old floppies are notorious for bit rot, I'll be using ddrescue to make the images which is basically dd with added fault tolerance and error correction. So far, I've been able to pull images from a couple of the disks with relatively little issue.

Not that I expected anything different, but the disk images are not mountable and no software I've tried recognizes them as anything but a block of incomprehensible data.