Like — said SVN is fine but it's a lot of merging and manual effort to do something like bring in elements from one project to another.
I think I get what the intent is here and it's not about project file merging it's really "there's a sprite and a background and a layout I want from project1 that I want to use in project2" and how do I get it?
Will post code shortly that will do this for you.
Thanks.