I have no input to offer on the box, but I was reading this thread while listening to the radio. The guy on the radio just happened to say chromium. It isn't a show related to shaving, science, metals, etc. That was a funny little coincide. Love it.
Silver, gold, and chrome are the only original finish that I'm aware of for new standard style razors.
Gillette used nickel on many more razors later on and rhodium plating on some of the highest end razors. Also painted some razors like Techs that are black and the tips of the red and blue Super Speed.
Generally speaking I have believed that the New Improved/Standard razors were mostly silver and gold plated. There are some Chrome plated.
Check yours inside. If the barrel is the same finish bottom to top. The gold and silver ones I've seen almost all appear to be worn or not fully plated to the tip where the threads are. Chrome tends to chip rather than wear smoothly. Chrome will not tarnish either and has a mirror like finish that's a brighter color than silver.
[MENTION=60571]drab[/MENTION], yours looks silver plated to me.