Indeed good advice, Bob. And in fact our first attempt at shipping the gearbox was with DHL and with them part of the weighbill is put into the crate before the lid is screwed down. But then they decided that they wouldn't accept it as it hadn't been steam cleaned! Oddly, UPS didn't require any paperwork in the crate and it never crossed our minds that it made sense to do so. Once bitten, twice shy, eh?
The same thing, ie address inside the object, is a good idea for aircraft luggage. Once the barcode outside the suitcase is lost then there is now way of knowing whence it came and wither it was going. An internal identifier can at least identify to whom it belongs.
Great news that you've found where it came to rest. I have had a couple of near misses, where drivers have dropped at wrong addresses etc. I NEVER trust labels and always write the address in marker pen on the packaging as a back up, plus my e mail address.