Thank you to everyone for your suggestions.
I have been celebrating my birthday early 
, but will try them out tomorrow and report.
I was looking at the photo and it seemed that the pins just lined up, but when I did that (using both an old floppy cable, and standard jumper wires), I got no backlight when I applied power to the arduino. I assumed that the pot would be a single turn jobber, not a 22 turn.....I gave it a 60 degree twist left and right (because that's all it took on the ones I bought from my local chip shop), and got nothing.
And I saw the other posts about changing the constructor, and asked wtf they would do that and not just keep one standard way of doing it. But that would take all the fun out of it, right?
And yes, sometimes I get that "it's no good, eff it, and chuck it into my toy box" attitude. But before I do that, I check with the experts.
I finally got an answer back from the seller. They sent me the docs. Too bad I don't speak Chinese.... 
They promised to send me the English ones asap. I'm betting that I will have it running long before then.
Again, thanks to all, and I will report back.