I found one of the designs in the Sandbox design competition that I liked, but wanted to make some changes. I pretty much just liked the layout. I've figured out enough code that I can make the changes I want, which are fairly substantial. I'm more familiar with working in Livejournal and the standard there is to credit someone for the underlying code if you alter a fair amount of code, which I would do.
Should I contact the original designers and let them know that I'm using their entry in the competition and making changes to it? Should I get their approval? The support page listed in the documentation no longer exists. I don't want to step on anyone's toes.