Some time ago, DropBox chose to disable old public folders and break all old download links. I haven't yet taken the time to re-upload the older versions or replace all of the old links, although I still have the files sitting around somewhere.
For now, I just disabled many of the links for older versions, and uploaded the Minecraft 1.0.0 ones to the WIP uristqwerty.ca listing, replacing the corresponding direct links in the OP. There's enough of an archive that I probably won't fix every old link today, but if there are any other versions that are especially important to anybody, please say so!
Also, I need to figure out something for the extras, since the keybind and potion recipes weren't bundled back then, and I haven't set up a region on the site for them.
In unrelated news, I recently started playing GTNH and discovered that the built-in GT support is broken and incomplete. Fixing it is also revealing areas that could use API enhancement, so there might be a 126.96.36.199 for 1.7.10+ eventually. Probably weeks away at minimum, since pack startup time is massive, GT is complex, and I want any API improvements to be carefully considered and tested before any public releases.