Unix Exec MIDI files not opening in Logic 11.1

I have several Gigabytes of legacy original music files some dating back to the early 1990's that appear as "Unix Execuitable" files in my Finder. They will not open even if I add a ".mid" suffex to them and were all authored using products like Performer, Band in A Box, Protools and Logic. I always made SMF copies of my material for portability and now it seems I am screwed when trying to recover and make use of these files.

I could not find any reference on how to convert these and I also tried the get info window to change the files opening with logic. But that doesn't seem to be the problem, the problem appears to be in how the data was written.

any help?? please and thank you

[Re-Titled by Moderator]