Here's my thoughts on what you've got so far.  
 *For the paragraph based on Almonte's journal, is that the historical analysis of the journal or Almonte's own words.  I'm not comfortable citing directly to a primary source.  Lindley also mentioned that Almonte used that number (although not the detail in that paragraph), so we could cite to him if we need to. 
 *I don't think we need the details of Damacio Jimenez in the lead 

 I actually had a different vision of the lead.  I would have structured it similarly to this: 
 *How people got there 
 **Mexico besieged the Alamo beginning Feb 23.  At the time, there were X number of Texians garrisoned there.  Some of the men who were out doing stuff weren't able to re-enter because of Mexican troops; others did. 
 **Travis sent letters - lots of letters - asking for reinforcements.  Members of the garrison were sent out as couriers to deliver them.  
 **Purported amnesty and the Tejanos left too (I think I read somewhere that they were trying to protect their families/property) 
 **Volunteers were gathering in Gonzales to try to reinforce the mission.  32 made it in on March 1. 
 **Fannin, leader of the other garrison in Texas, attempted to reinforce the mission; made it 2 miles and turned back 
 **some of Fannin's men, some of the couriers, and others who wanted to join the effort attempted to reinforce the mission on March 4.  Approximately 50 made it inside; the others were turned back by Mexican troops 
 **Mexican troops launched an all-out assault on March 6 and killed almost all of the defenders in the Alamo at that time.  
 *How many were there? 
 **Almonte's numbers 
 **Telegraph and Texas Register list compiled 
 **Ruiz 
 **Military land grants used muster rolls and sworn statements of witnesses. Lindley has some of this, Lack may have more 
 **There was an 1881 monument that had a list of names.  It burned down. No record of who was on that list. I will have to think on where I saw that information. 
 **First comprehensive historical look at the names was Amelia Williams' doctoral dissertation, where she identified 182 names.  These were used for the official list on the Alamo Cenotaph erected in 1936 
 **Later historians have cast doubts on the accuracy of Williams' list, finding some people on the list who were not defenders and finding other omissions. 
 **Research continues to be done and there is likely never going to be a definitive count