Can't post most of my manuals

I have a LOT of manuals to still contribute, but any files that are more than a little over 100 MB get Error 413 for being "too large" despite the stated 1 GB limit. In addition, a few that are small enough don't make it through because the uploader sees some files as double with the duplicate having an additional _MacOSX_ before the file name and the process is halted.

Can anyone help me? :(