the unofficial BibleWorks blog are (to the best of our knowledge) free of such concerns. This was the problem with Robin Song's files and is the same problem with the New World Translation (though that also fails to meet public domain pre-1923).
Wycliffe is precisely a case in point. His translation is available online at http://wesley.nnu.edu/sermons-essays...s-translation/, but I have not been able to get permission from them to convert it into a redistributable BW version. I had mistakenly assumed since it was freely downloadable for personal use that it could be redistributed in another format, but this is not the case.
That being said, you could download it and convert it for your own use with no repercussions, as far as I know.
I have no idea what you would do to convert it to Mac. You don't have to ask to download for personal use; they would not give permission for free use to redistribute. The link you have listed should not be active. I'll contact Michael to have it removed from their site.
www.copyright.gov confirming that copying an out of copyright work to a new format does not make that new format copyrighted unless it is changed.