Trailer number vs. actual lengths just don't match up most of the time. I would use the total length of the trailer as the reference, especially when making campground reservations. You can't remove the tongue to whittle the trailer down to 24'.
Pictures of the numbers you refer to would be good so someone might establish a model number for you....as well as the year of your trailer. Also, pictures of the inside and outside might help if someone already has that model trailer here on the forum.
Chap , DW Joy, and Fur Baby Sango
2006 Ford F150 Super Cab 4x4
2008 Surveyor 263