I'm new to OS level programming so apologies for the noobness.
Ultimately I would like to change the behaviour of clicking on "Change Desktop Background" from the desktop context menu. It would appear the Nautilus package contains the source and I have even found the line which calls the Desktop Control Panel after clicking on "Change Desktop Background".
Is it possible to re-compile the modified version of Nautilus, test it, and install it on my own system? This could be ultra noob asking a question like this but I just don't know yet!