The latest 060 libs are available on
Aminet but those Are Phase5 libs so I don't know if they are newer than those you already have.
About renaming the libs.. that is correct.. you'll have these files in your libs when done:
68060.library - the new 68060.library
68040.library - "dummy lib" linking to right lib for compability
68040old.library - your old 68040.library
68040new.library - the new "real" 68040.library needed for the 060 and "dummy lib".
