Just about every federation has the same specs. I am not sure what the AAU has listed, but that seems WAY off. 24" wide? A 2 foot wide bench? Not likely
Height is pretty much the same anywhere you go. IPA, IPF, APA, etc.
16.5" to 17.75" tall (42-45cm) - (from the ground, to the top of the padded surface, when the surface is UNCOMPRESSED)
Width will be 11.5" to 12 5/8"
Length of the entire pad will not be less than 48" ...usually they are around 50 for a standard comp bench.
I think you will see most every rule book list these same rules.
If you look on my website on my links page, I have the links to the various federations. Most of the federation websites have online rule books that list the specifics.
Hope this helps.