I was given a large amount of spare Glock parts. The problem is that I'm having trouble identifying which model some of them fit. The universal ones are easy but the ones that are specific to a particular model are giving me a problem. The numbers marked on the parts don't match any numbers on my current parts list. And some parts don't have any numbers at all on them. Slide stop lever numbers don't match my list, some firing pins aren't marked, trigger housing numbers don't match, trigger/bar assemblies aren't marked. Some of these are probably old parts and the numbers have changed ? Do I need an old parts list to look them up, or is there somewhere I can get detailed photos so the I can match them up? Any help is greatly appreciated. Thanks!