So what do you do when you have a “backup” that you have in .BIN,.CUE files and it needs to be mounted as an .ISO?

Bchunk is your friend here:

#> bchunk [target basename]

The first two directives are self-explanatory.  The third is the target base filename prepended by the location (if outside the current directory).  Here’s an example:

You have two files: cd-image.bin and cd-image.cue.  You’re in your home directory.  You want your newly created .ISO to be in /tmp as /tmp/cd-image.iso.  Here’s what you do:

#> bchunk cd-image.bin cd-image.cue /tmp/cd-image

Notice that I left off the .ISO at the end.  bchunk adds that for us.  I recommend adding the -v switch for verbosity.