Thought I'd post this response here as a clarification of what I was looking to do, in case I wasn't initially clear.
Well, it's not behind a hardware write blocker if that's what you implied by
If the physical media is read-only, then don't worry - you're not going to change anything.
Really the only write block protection I've been doing to it is to specify the switch -oro to tell it that it's read only. Then, when I want to cd into the mounted filesystem and view, say, the contents of a file that has permissions of 000 (I changed it that way on a test drive, for experimentation), it won't let me.
If I take off the write blocking I can, but that changes the drive! And thank you for the links I'll continue to investigate further.