In Mount and Blade Warband, I want to stop being Swadian rebels

I believe that there is a theoretical maximum on the renown (people have reported that over 2000 renown it gets increasingly difficult). I presume that the diminishing effect of this cap is not stated in the calculations before the tournaments/battles and will be when you actually get the renown.

This probably results in the effect you are having, you get 24 renown from the battle stated, before the diminishing returns are calculated.

The formula to calculate renown works as follows:
The higher your renown, the less renown you gain for the same activities. Any time you gain renown, the game takes your previous renown, divides it by 200, then subtracts the result from the renown that you just gained.

Or, as a formula:

Actual Renown Increase = Stated Amount - (Current/200)

So, in order to gain 7 when it says you gain 30, you would need to already have 7400 renown:

7 = 30 - (Current/200)
Current/200 = 37
Current = 7400

Source: http://forums.taleworlds.com/index.php/topic,115829.0.html

You can get all the patches from the TaleWorlds official website. Just select your game and go to the download section, and it will be here, either in patch or directly download the latest version.

Note that 1.54 should only bring modifications relative to NW, and the mod should work under 1.53 if if doesn't use any NW specific content, So the latest real Warband native version is 1.53, that you already have.