That is a good question. With out a real answer.
http://www.ofrei.com
You can call these guys and they can probably find what you need. Here is the problem. There are so many watches and even the same watch may not have the same movement. It can get very confusing and impossible for an amature to figure it out.
In this case I got very lucky. The 2804-2 movement is the same movement used in the level one watch offered in the time zone watch class. Otto Frei supplies the parts for the watch class. And they know students will break and loose all the parts. So they have them all listed and numbered and in stock.