No luck searching for it... (notoriously difficult to google), but I suspect some Chinese maker... but why "WJ" then? Some retailer brand?
I got it for a few bucks on a Swedish ebay equivalent, which is why I know nothing about it. (The seller didn't either.)
Btw, I have picked both sides, not very easy and the side with the sticker is slightly harder. (They are different, there's some master key scheme here, as can be seen on the last cut of the keys; two of them only open one side of the lock.)
