[ashlar]

Thanks for that. Unfortunately I don't have time to go through my entire collection and add 24hz to the necessary files

You could use something like Advanced Renamer and completely automate the process.

I just downloaded it and with two rules I got a result that would suit your needs.
You would use two "Add" rules. I did the work for you.

Copy the following in a text file. Save it with the name you prefer (MovieFramerateRenamer for instance), with a .aren extension. You then import it through "Load Method List", select your movie folders and the work is done. You always have a preview of how the filename is going to be renamed, just to be sure.

Code:

[header]
type=preset
application=Advanced Renamer 3.71
application_version=3710000
batchmode=rename

[namecollision]
separator=_
pattern=
rule=fail

[methods]
method0000=methodname:"add"; active:"1"; position:"0"; add:"<Video FrameRate>"; backwards:"1"; applyto:"name"; regularexpressions:"0";
method0001=methodname:"add"; active:"1"; position:"6"; add:"."; backwards:"1"; applyto:"name"; regularexpressions:"0";