You should be able to scrape the paint or paper off the cassette down to metal.

You can check your camera to see what type of sensors it has. Some cameras have two contacts for each metal patch, and check continuity at two places on the same patch. Other cameras use patch "G" as a 'ground' and check for continuity between that patch and whatever other may be exposed. You can read more about it here.

The easiest thing to do is to get some DX coded film and just copy the pattern by scraping with a knife.