Numbers are correct, as I've now manually successfully decoded it.
In terms of documentation, I've made and coded these sensors myself, I just didn't entirely understand how the data was encoded with the library (RadioHead ASK).
Now just need to figure out a command line binary to IEEE 754 floating point number conversion.
Bash doesn't do floating point, but I still expected it to be a simple case of calling bc or something, but nothing useful comes up from relevant searches.
Guess you'll have to convert your manual steps to Perl or Python?