A properly dumped ISO file is a bit-for-bit copy of the CD, preserving it perfectly, and can be done from Windows. You need a program that will create an ISO direct from the drive, not from the mounted files. I haven't done this myself so I can't recommend a program, but Google offers plenty of suggestions and maybe others have experience. Feel free to email me if you'd like help testing a dumped ISO.
On the Power Mac, you could use Apple's Disk Copy to create a shareable disk image, or even something like StuffIt to capture the contents. A modern OS X machine can read either of those and convert them into a more accessible format. These methods wouldn't create an identical full copy like an ISO, but it would preserve all the important data and metadata.
Comparing your screenshots to my standard Trilogy disc, it looks the same with a new Read Me file (the gibberish file name would appear correctly on a Japanese Mac) and potentially new additions. Nothing on the English-language disc is dated past April; your screenshots show some August dates. You might have unique items in Marathon > Solo Maps, for instance, but the folder you picked looks the same.
Most of the M2/Infinity net maps should be playable without any conversion. Just add ".sceA" to the end of a map file name and you can open it in Aleph One or Weland. Terminals will be lost without special handling, which is an issue for solo maps. The accompanying read-me files are usually text: add ".txt" and open in Notepad.
