If nothing else works out, here are two hacks:

Using an image editing program, I've typed text over the image used for the phone's background image (not an iPhone, but it looks like it would work). The way the iPhone works, once unlocked, the icons might cover over the text in a way that's not annoying or distracting.

Hack #2: A label with the essentials, made with a Brother P-Touch, stuck to the back of the phone. Works even if the battery is toast.